Golf shafts having a varying outer diameter, inner diameter, and/or wall thickness and methods for manufacturing golf shafts using additive manufacturing

ABSTRACT

A method for manufacturing a golf shaft may include receiving a CAD model corresponding to the golf shaft, and forming, based at least in part on the CAD model, the golf shaft using one or more additive manufacturing techniques. The golf shaft may include a first end and a second end disposed opposite one another along a longitudinal axis of the golf shaft, and the golf shaft may define one or more internal cavities extending along the longitudinal axis. The golf shaft may have an overall length from the first end to the second end, an outer diameter, an inner diameter, and a wall thickness, and at least one of the outer diameter, the inner diameter, and the wall thickness may vary along the overall length.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of, and priority to, U.S.Provisional Patent Application No. 63/253,730, filed on Oct. 8, 2021,and titled “Golf Shafts Having a Varying Outer Diameter, Inner Diameter,and/or Wall Thickness and Methods for Manufacturing Golf Shafts UsingAdditive Manufacturing,” the disclosure of which is expresslyincorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to golf clubs and moreparticularly to golf shafts having a varying outer diameter, innerdiameter, and/or wall thickness and related methods for manufacturinggolf shafts having a varying outer diameter, inner diameter, and/or wallthickness using additive manufacturing.

BACKGROUND OF THE DISCLOSURE

Golf clubs generally include three components: a shaft, a grip, and aclubhead. Of these components, the shaft typically is considered themost influential in determining the overall performance of a golf cluband thus often may be referred to as the “engine” of the club. Each golfshaft has a stiffness profile that dictates how the shaft flexes whenswung by a user during a golf swing. The weight of a golf shaft and howit flexes generally are the key factors in controlling swing speed andoutput ball flight dynamics, such as launch angle, launch direction, andspin rate. These dynamics ultimately may determine the distance andaccuracy of a golf shot.

Steel golf shafts traditionally may be manufactured by first drawing athick-walled tube down into a thin-walled tube. Then, individualsections of the thin-walled tube may be squeezed to reduce the diametersof the respective sections and create “steps” in the golf shaft.Notably, this manufacturing technique typically requires large assemblylines and expensive machinery that can be used to economically make golfshafts of only a few different stiffnesses. Moreover, this techniquegenerally is not capable of varying the stiffness profile continuouslyalong the length of a golf shaft, thereby limiting the designcapabilities of the process. Consequently, current golf shaft providerstypically lump golfers into a select number of shaft stiffness “bins”based on a golfer's swing speed, with each bin covering a relativelylarge range of swing speeds. For example, certain providers may use fivedifferent shaft stiffness bins in recommending a golf shaft for aparticular golfer: an “Extra-Flexible” bin for those with a swing speedof 62 mph or less, a “Flexible” bin for those with a swing speed of 63mph to 76 mph, a “Regular” bin for those with a swing speed of 77 mph to92 mph, a “Stiff” bin for those with a swing speed of 93 mph to 107 mph,and an “Extra Stiff” bin for those with a swing speed of 108 mph orgreater. This approach may result in two different golfers havingsignificantly different swing speeds being lumped into the same bin. Forexample, a golfer with a swing speed of 78 mph and another golfer with aswing speed of 91 mph both would be fit into a Regular golf shaft eventhough their swing speeds are 13 mph apart and will result in differentshaft loading patterns. Ultimately, the traditional bin approach oftenmay result in a particular golfer using a shaft that is not ideal forhis/her golf swing, thereby resulting in a loss of shot distance and/ordecreased accuracy.

A need therefore exists for improved golf shafts and related methods formanufacturing golf shafts, which may overcome one or more of theabove-mentioned limitations associated with traditional golf shafts andtechniques for manufacturing such golf shafts.

SUMMARY OF THE DISCLOSURE

The present disclosure provides golf shafts, golf clubs, and relatedmethods for manufacturing golf shafts. In one aspect, a method formanufacturing a golf shaft is provided. In one embodiment, the methodmay include receiving a CAD model corresponding to the golf shaft, andforming, based at least in part on the CAD model, the golf shaft usingone or more additive manufacturing techniques. The golf shaft mayinclude a first end and a second end disposed opposite one another alonga longitudinal axis of the golf shaft, and the golf shaft may define oneor more internal cavities extending along the longitudinal axis. Thegolf shaft may have an overall length from the first end to the secondend, an outer diameter, an inner diameter, and a wall thickness, and atleast one of the outer diameter, the inner diameter, and the wallthickness may vary along the overall length.

In some embodiments, forming the golf shaft using one or more additivemanufacturing techniques may include forming the golf shaft of one ormore metals or metal alloys using one or more metal additivemanufacturing techniques. In some embodiments, forming the golf shaftusing one or more additive manufacturing techniques may include formingthe golf shaft using one or more powder bed fusion techniques. In someembodiments, forming the golf shaft using one or more additivemanufacturing techniques may include forming the golf shaft as a singlecomponent using the one or more additive manufacturing techniques. Insome embodiments, the method also may include determining user datacorresponding to a swing pattern of a predetermined user of the golfshaft, and generating the CAD model based at least in part on the userdata. In some embodiments, the method also may include determining astiffness profile of the golf shaft based at least in part on the userdata, and generating the CAD model based at least in part on the userdata may include generating the CAD model based at least in part on thestiffness profile. In some embodiments, the golf shaft further also mayinclude an external geometric structure disposed along an outer surfaceof the golf shaft, and wherein the external geometric structure has apattern of geometric shapes. In some embodiments, at least a portion ofthe golf shaft may be devoid of any cylindrical thin-walled segments.

In another aspect, a method for manufacturing a golf shaft is provided.In one embodiment, the method may include receiving a CAD modelcorresponding to the golf shaft, and forming, based at least in part onthe CAD model, the golf shaft using one or more additive manufacturingtechniques. The golf shaft may include a first end and a second enddisposed opposite one another along a longitudinal axis of the golfshaft, and the golf shaft may define one or more internal cavitiesextending along the longitudinal axis. The golf shaft may have anoverall length from the first end to the second end, an outer diameter,an inner diameter, and a wall thickness, and the wall thickness may varyalong the overall length. A variation of the wall thickness between anytwo cross-sections of the golf shaft taken perpendicular to thelongitudinal axis is equal to or greater than 0.001 inches.

In some embodiments, at least one of the inner diameter or the outerdiameter may vary in a non-linear manner along at least a portion of thegolf shaft. In some embodiments, at least one of the inner diameter orthe outer diameter may vary along at least a portion of the golf shaftsuch that a taper rate of the at least one of the inner diameter or theouter diameter changes more than once along the at least a portion ofthe golf shaft. In some embodiments, forming the golf shaft using one ormore additive manufacturing techniques may include forming the golfshaft of one or more metals or metal alloys using one or more metaladditive manufacturing techniques. In some embodiments, forming the golfshaft using one or more additive manufacturing techniques may includeforming the golf shaft as a single component using the one or moreadditive manufacturing techniques. In some embodiments, the method alsomay include determining user data corresponding to a swing pattern of apredetermined user of the golf shaft, and generating the CAD model basedat least in part on the user data. In some embodiments, the method alsomay include determining a stiffness profile of the golf shaft based atleast in part on the user data, and generating the CAD model based atleast in part on the user data may include generating the CAD modelbased at least in part on the stiffness profile. In some embodiments,the golf shaft also may include an internal lattice structure disposedwithin at least one of the one or more internal cavities. In someembodiments, the golf shaft also may include an external geometricstructure disposed along an outer surface of the golf shaft, and theexternal geometric structure may have a pattern of geometric shapes.

In still another aspect, a method for manufacturing a golf shaft isprovided. In one embodiment, the method may include receiving a CADmodel corresponding to the golf shaft, and forming, based at least inpart on the CAD model, the golf shaft using one or more additivemanufacturing techniques. The golf shaft may include a first end, asecond end disposed opposite the first end along a longitudinal axis ofthe golf shaft, with the golf shaft having an overall length from thefirst end to the second end, a shaft body extending from the first endto the second end and having an outer surface, with the shaft bodydefining an internal cavity extending along the longitudinal axis, andan external geometric structure disposed along the outer surface, withthe external geometric structure having a pattern of geometric shapes.

In some embodiments, the pattern of geometric shapes may be a repeatingpattern. In some embodiments, the pattern of geometric shapes may be anon-repeating pattern.

In one aspect, a method for manufacturing a golf shaft is provided. Inone embodiment, the method may include receiving a CAD modelcorresponding to the golf shaft, and forming, based at least in part onthe CAD model, the golf shaft using one or more additive manufacturingtechniques. The golf shaft may include a first end and a second enddisposed opposite one another along a longitudinal axis of the golfshaft, and the golf shaft may define one or more internal cavitiesextending along the longitudinal axis. The golf shaft may have anoverall length from the first end to the second end, an outer diameter,an inner diameter, and a wall thickness, and at least one of the outerdiameter, the inner diameter, and the wall thickness may vary along theoverall length.

In some embodiments, forming the golf shaft using one or more additivemanufacturing techniques may include forming the golf shaft of one ormore metals or metal alloys using one or more metal additivemanufacturing techniques. In some embodiments, the one or more metals ormetal alloys may include at least one of: steel, a steel alloy,titanium, a titanium alloy, aluminum, or an aluminum alloy. In someembodiments, forming the golf shaft using one or more additivemanufacturing techniques may include forming the golf shaft using one ormore powder bed fusion techniques. In some embodiments, the one or morepowder bed fusion techniques may include at least one of: direct metallaser sintering, selective laser melting, or electron beam melting. Insome embodiments, forming the golf shaft using one or more additivemanufacturing techniques may include forming the golf shaft using one ormore metal binder jetting techniques. In some embodiments, the one ormore metal binder jetting techniques may include 3D printing. In someembodiments, forming the golf shaft using one or more additivemanufacturing techniques may include forming the golf shaft using one ormore direct energy deposition techniques. In some embodiments, the oneor more direct energy deposition techniques may include at least one of:laser engineered net shaping, direct metal deposition, or laser metaldeposition. In some embodiments, forming the golf shaft using one ormore additive manufacturing techniques may include forming the golfshaft using metal material extrusion. In some embodiments, forming thegolf shaft using one or more additive manufacturing techniques mayinclude forming the golf shaft using one or more material jettingtechniques. In some embodiments, the one or more material jettingtechniques may include liquid metal additive manufacturing. In someembodiments, forming the golf shaft using one or more additivemanufacturing techniques may include forming the golf shaft using atleast one of: joule printing, digital light projection metal printing,or cold spray metal printing. In some embodiments, forming the golfshaft using one or more additive manufacturing techniques may includeforming the golf shaft as a single component using the one or moreadditive manufacturing techniques. In some embodiments, forming the golfshaft using one or more additive manufacturing techniques may includeseparately forming two or more segments of the golf shaft using the oneor more additive manufacturing techniques, and the method also mayinclude fixedly coupling the two or more segments of the golf shaft toone another. In some embodiments, fixedly coupling the two or moresegments of the golf shaft to one another may include welding the two ormore segments of the golf shaft to one another. In some embodiments, themethod also may include determining user data corresponding to a swingpattern of a predetermined user of the golf shaft, and generating theCAD model based at least in part on the user data. In some embodiments,the method also may include determining a stiffness profile of the golfshaft based at least in part on the user data, and generating the CADmodel based at least in part on the user data may include generating theCAD model based at least in part on the stiffness profile. In someembodiments, the outer diameter may vary along the overall length. Insome embodiments, the inner diameter may vary along the overall length.In some embodiments, the wall thickness may vary along the overalllength. In some embodiments, the outer diameter and the inner diametereach may vary along the overall length. In some embodiments, the outerdiameter and the wall thickness each may vary along the overall length.In some embodiments, the inner diameter and the wall thickness each mayvary along the overall length. In some embodiments, the outer diameter,the inner diameter, and the wall thickness each may vary along theoverall length.

In another aspect, a golf shaft is provided. In one embodiment, the golfshaft may include a first end and a second end disposed opposite oneanother along a longitudinal axis of the golf shaft. The golf shaft maydefine one or more internal cavities extending along the longitudinalaxis. The golf shaft may have an overall length from the first end tothe second end, an outer diameter, an inner diameter, and a wallthickness. At least one of the outer diameter, the inner diameter, andthe wall thickness may vary along the overall length.

In some embodiments, the outer diameter may vary along the overalllength. In some embodiments, the inner diameter may vary along theoverall length. In some embodiments, the wall thickness may vary alongthe overall length. In some embodiments, the outer diameter and theinner diameter each may vary along the overall length. In someembodiments, the outer diameter and the wall thickness each may varyalong the overall length. In some embodiments, the inner diameter andthe wall thickness each may vary along the overall length. In someembodiments, the outer diameter, the inner diameter, and the wallthickness each may vary along the overall length.

In some embodiments, the golf shaft may include a first shaft portionand a second shaft portion each disposed between the first end and thesecond end, the outer diameter may decrease along the first shaftportion in a direction from the first end toward the second end, and theouter diameter may increase along the second shaft portion in thedirection from the first end toward the second end. In some embodiments,the golf shaft may include a first shaft portion and a second shaftportion each disposed between the first end and the second end, theinner diameter may decrease along the first shaft portion in a directionfrom the first end toward the second end, and the inner diameter mayincrease along the second shaft portion in the direction from the firstend toward the second end. In some embodiments, the golf shaft mayinclude a first shaft portion and a second shaft portion each disposedbetween the first end and the second end, the wall thickness maydecrease along the first shaft portion in a direction from the first endtoward the second end, and the wall thickness may increase along thesecond shaft portion in the direction from the first end toward thesecond end. In some embodiments, the golf shaft may be formed of one ormore metals or metal alloys. In some embodiments, the one or more metalsor metal alloys may include at least one of: steel, a steel alloy,titanium, a titanium alloy, aluminum, or an aluminum alloy.

In still another aspect, a golf club is provided. In one embodiment, thegolf club may include a golf shaft, a grip, and a clubhead. The golfshaft may include a first end and a second end disposed opposite oneanother along a longitudinal axis of the golf shaft, a grip sectionextending from the first end toward the second end, and a clubheadsection extending from the second end toward the first end. The golfshaft may define one or more internal cavities extending along thelongitudinal axis. The golf shaft may have an overall length from thefirst end to the second end, an outer diameter, an inner diameter, and awall thickness. At least one of the outer diameter, the inner diameter,and the wall thickness may vary along the overall length. The grip maybe coupled to the grip section, and the clubhead may be coupled to theclubhead section.

In one aspect, a method for manufacturing a golf shaft is provided. Inone embodiment, the method may include receiving a CAD modelcorresponding to the golf shaft, and forming, based at least in part onthe CAD model, the golf shaft using one or more additive manufacturingtechniques. The golf shaft may include a first end and a second enddisposed opposite one another along a longitudinal axis of the golfshaft, and the golf shaft may define one or more internal cavitiesextending along the longitudinal axis. The golf shaft may have anoverall length from the first end to the second end, and a wallthickness of the golf shaft may continuously vary along at least 5% ofthe overall length.

In another aspect, a golf shaft is provided. In one embodiment, the golfshaft may include a first end, and a second end disposed opposite thefirst end along a longitudinal axis of the golf shaft. The golf shaftmay be formed of one or more metals or metal alloys. The golf shaft maydefine one or more internal cavities extending along the longitudinalaxis. The golf shaft may have an overall length from the first end tothe second end. A wall thickness of the golf shaft may continuously varyalong at least 5% of the overall length.

In some embodiments, the wall thickness may continuously vary along atleast 10% of the overall length. In some embodiments, the wall thicknessmay continuously vary along at least 20% of the overall length. In someembodiments, the wall thickness may continuously vary along at least 30%of the overall length. In some embodiments, the wall thickness maycontinuously vary along at least 40% of the overall length. In someembodiments, the wall thickness may continuously vary along at least 50%of the overall length. In some embodiments, the wall thickness maycontinuously vary along at least 60% of the overall length. In someembodiments, the wall thickness may continuously vary along at least 70%of the overall length. In some embodiments, the wall thickness maycontinuously vary along at least 80% of the overall length. In someembodiments, the wall thickness may continuously vary along at least 90%of the overall length. In some embodiments, the wall thickness maycontinuously vary along an entirety of the overall length. In someembodiments, the wall thickness may be constant along a minority of theoverall length.

In some embodiments, the golf shaft also may include a shaft portiondisposed between the first end and the second end, and the wallthickness may continuously decrease along the shaft portion in adirection from the first end toward the second end. In some embodiments,an outer diameter of the golf shaft may continuously decrease along theshaft portion in the direction from the first end toward the second end.In some embodiments, the outer diameter of the golf shaft maycontinuously decrease in a linear manner along the shaft portion in thedirection from the first end toward the second end. In some embodiments,the outer diameter of the golf shaft may continuously decrease in anon-linear manner along the shaft portion in the direction from thefirst end toward the second end. In some embodiments, the outer diameterof the golf shaft may continuously decrease at an increasing rate alongat least part of the shaft portion in the direction from the first endtoward the second end. In some embodiments, the outer diameter of thegolf shaft may continuously decrease at a decreasing rate along at leastpart of the shaft portion in the direction from the first end toward thesecond end. In some embodiments, an inner diameter of the golf shaft maycontinuously increase along the shaft portion in the direction from thefirst end toward the second end. In some embodiments, the inner diameterof the golf shaft may continuously increase in a linear manner along theshaft portion in the direction from the first end toward the second end.In some embodiments, the inner diameter of the golf shaft maycontinuously increase in a non-linear manner along the shaft portion inthe direction from the first end toward the second end. In someembodiments, the inner diameter of the golf shaft may continuouslyincrease at an increasing rate along at least part of the shaft portionin the direction from the first end toward the second end. In someembodiments, the inner diameter of the golf shaft may continuouslyincrease at a decreasing rate along at least part of the shaft portionin the direction from the first end toward the second end. In someembodiments, an inner diameter of the golf shaft may continuouslydecrease along the shaft portion in the direction from the first endtoward the second end. In some embodiments, an inner diameter of thegolf shaft may be constant along the shaft portion. In some embodiments,an inner diameter of the golf shaft may continuously increase along theshaft portion in the direction from the first end toward the second end.In some embodiments, the inner diameter of the golf shaft maycontinuously increase in a linear manner along the shaft portion in thedirection from the first end toward the second end. In some embodiments,the inner diameter of the golf shaft may continuously increase in anon-linear manner along the shaft portion in the direction from thefirst end toward the second end. In some embodiments, the inner diameterof the golf shaft may continuously increase at an increasing rate alongat least part of the shaft portion in the direction from the first endtoward the second end. In some embodiments, the inner diameter of thegolf shaft may continuously increase at a decreasing rate along at leastpart of the shaft portion in the direction from the first end toward thesecond end. In some embodiments, an outer diameter of the golf shaft maycontinuously increase along the shaft portion in the direction from thefirst end toward the second end. In some embodiments, an outer diameterof the golf shaft may be constant along the shaft portion. In someembodiments, the shaft portion may extend from the first end and may bespaced apart from the second end. In some embodiments, the shaft portionmay be spaced apart from the first end and may extend to the second end.In some embodiments, the shaft portion may be spaced apart from each ofthe first end and the second end.

In some embodiments, the golf shaft also may include a shaft portiondisposed between the first end and the second end, and the wallthickness may continuously increase along the shaft portion in adirection from the first end toward the second end. In some embodiments,an outer diameter of the golf shaft may continuously increase along theshaft portion in the direction from the first end toward the second end.In some embodiments, the outer diameter of the golf shaft maycontinuously increase in a linear manner along the shaft portion in thedirection from the first end toward the second end. In some embodiments,the outer diameter of the golf shaft may continuously increase in anon-linear manner along the shaft portion in the direction from thefirst end toward the second end. In some embodiments, the outer diameterof the golf shaft may continuously increase at an increasing rate alongat least part of the shaft portion in the direction from the first endtoward the second end. In some embodiments, the outer diameter of thegolf shaft may continuously increase at a decreasing rate along at leastpart of the shaft portion in the direction from the first end toward thesecond end. In some embodiments, an inner diameter of the golf shaft maycontinuously decrease along the shaft portion in the direction from thefirst end toward the second end. In some embodiments, the inner diameterof the golf shaft may continuously decrease in a linear manner along theshaft portion in the direction from the first end toward the second end.In some embodiments, the inner diameter of the golf shaft maycontinuously decrease in a non-linear manner along the shaft portion inthe direction from the first end toward the second end. In someembodiments, the inner diameter of the golf shaft may continuouslydecrease at an increasing rate along at least part of the shaft portionin the direction from the first end toward the second end. In someembodiments, the inner diameter of the golf shaft may continuouslydecrease at a decreasing rate along at least part of the shaft portionin the direction from the first end toward the second end. In someembodiments, an inner diameter of the golf shaft may continuouslyincrease along the shaft portion in the direction from the first endtoward the second end. In some embodiments, an inner diameter of thegolf shaft may be constant along the shaft portion. In some embodiments,an inner diameter of the golf shaft may continuously decrease along theshaft portion in the direction from the first end toward the second end.In some embodiments, the inner diameter of the golf shaft maycontinuously decrease in a linear manner along the shaft portion in thedirection from the first end toward the second end. In some embodiments,the inner diameter of the golf shaft may continuously decrease in anon-linear manner along the shaft portion in the direction from thefirst end toward the second end. In some embodiments, the inner diameterof the golf shaft may continuously decrease at an increasing rate alongat least part of the shaft portion in the direction from the first endtoward the second end. In some embodiments, the inner diameter of thegolf shaft may continuously decrease at a decreasing rate along at leastpart of the shaft portion in the direction from the first end toward thesecond end. In some embodiments, an outer diameter of the golf shaft maycontinuously decrease along the shaft portion in the direction from thefirst end toward the second end. In some embodiments, an outer diameterof the golf shaft may be constant along the shaft portion. In someembodiments, the shaft portion may extend from the first end and may bespaced apart from the second end. In some embodiments, the shaft portionmay be spaced apart from the first end and may extend to the second end.In some embodiments, the shaft portion may be spaced apart from each ofthe first end and the second end.

In some embodiments, the golf shaft also may include a first shaftportion disposed between the first end and the second end, and a secondshaft portion disposed between the first end and the second end. Thewall thickness may continuously decrease along the first shaft portionin a direction from the first end toward the second end, and the wallthickness may continuously increase along the second shaft portion inthe direction from the first end toward the second end. In someembodiments, the first shaft portion may be disposed between the firstend and the second shaft portion. In some embodiments, the first shaftportion may be disposed between the second end and the second shaftportion. In some embodiments, the first shaft portion and the secondshaft portion may be disposed adjacent one another. In some embodiments,the first shaft portion and the second shaft portion may be spaced apartfrom one another. In some embodiments, the golf shaft also may include athird shaft portion disposed between the first end and the second end,and the wall thickness may continuously decrease along the third shaftportion in the direction from the first end toward the second end. Insome embodiments, the golf shaft also may include a fourth shaft portiondisposed between the first end and the second end, the wall thicknessmay continuously increase along the third shaft portion in the directionfrom the first end toward the second end. In some embodiments, the golfshaft also may include a third shaft portion disposed between the firstend and the second end, and the wall thickness may continuously increasealong the third shaft portion in the direction from the first end towardthe second end. In some embodiments, an outer diameter of the golf shaftmay continuously decrease along at least a majority of the overalllength in a direction from the first end toward the second end. In someembodiments, an outer diameter of the golf shaft continuously maydecrease from the first end to the second end.

In some embodiments, the golf shaft also may include a grip sectionextending from the first end toward the second end, and a clubheadsection extending from the second end toward the first end. The gripsection may be configured to receive a grip thereon, and the clubheadsection may be configured to receive a clubhead thereon. In someembodiments, the wall thickness may continuously vary along the gripsection in a direction from the first end toward the second end. In someembodiments, the wall thickness may continuously decrease along the gripsection in the direction from the first end toward the second end. Insome embodiments, the wall thickness may continuously increase along thegrip section in the direction from the first end toward the second end.In some embodiments, the wall thickness may be constant along the gripsection. In some embodiments, the wall thickness may continuously varyalong the clubhead section in a direction from the first end toward thesecond end. In some embodiments, the wall thickness may continuouslydecrease along the clubhead section in the direction from the first endtoward the second end. In some embodiments, the wall thickness maycontinuously increase along the clubhead section in the direction fromthe first end toward the second end. In some embodiments, the wallthickness may be constant along the clubhead section.

In some embodiments, the one or more internal cavities may include aninternal cavity that extends from the first end to the second end. Insome embodiments, the one or more internal cavities may include aninternal cavity that extends from the first end toward the second endand is spaced apart from the second end. In some embodiments, the golfshaft also may include a shaft portion disposed between the internalcavity and the second end, and the shaft portion may be devoid of anyinternal cavities. In some embodiments, the shaft portion may extend tothe second end. In some embodiments, the one or more internal cavitiesmay include an internal cavity that extends from the second end towardthe first end and is spaced apart from the first end. In someembodiments, the golf shaft also may include a shaft portion disposedbetween the internal cavity and the first end, and the shaft portion maybe devoid of any internal cavities. In some embodiments, the shaftportion may extend to the first end. In some embodiments, the one ormore internal cavities may include an internal cavity that is spacedapart from each of the first end and the second end. In someembodiments, the golf shaft also may include a first shaft portiondisposed between the internal cavity and the first end, and a secondshaft portion disposed between the internal cavity and the second end.The first shaft portion may be devoid of any internal cavities, and thesecond shaft portion may be devoid of any internal cavities. In someembodiments, the first shaft portion may extend to the first end, andthe second shaft portion may extend to the second end. In someembodiments, the one or more internal cavities may include a firstinternal cavity and a second internal cavity that are not incommunication with one another. In some embodiments, the first internalcavity and the second internal cavity may be spaced apart from oneanother by a shaft portion that is devoid of any internal cavities. Insome embodiments, the first internal cavity may extend from the firstend toward the second end, and the second internal cavity may extendfrom the second end toward the first end. In some embodiments, the golfshaft may be formed of steel or a steel alloy. In some embodiments, thegolf shaft may be formed of titanium or a titanium alloy. In someembodiments, the golf shaft may be formed of aluminum or an aluminumalloy.

In still another aspect, a golf club is provided. In one embodiment, thegolf club may include a golf shaft, a grip, and a clubhead. The golfshaft may include a first end, a second end disposed opposite the firstend along a longitudinal axis of the golf shaft, a grip sectionextending from the first end toward the second end, and a clubheadsection extending from the second end toward the first end. The golfshaft may be formed of one or more metals or metal alloys. The golfshaft may define one or more internal cavities extending along thelongitudinal axis. The golf shaft may have an overall length from thefirst end to the second end. A wall thickness of the golf shaft maycontinuously vary along at least 5% of the overall length. The grip maybe coupled to the grip section, and the clubhead may be coupled to theclubhead section.

In one aspect, a method for manufacturing a golf shaft is provided. Inone embodiment, the method may include receiving a CAD modelcorresponding to the golf shaft, and forming, based at least in part onthe CAD model, the golf shaft using one or more additive manufacturingtechniques. The golf shaft may include a first end, and a second enddisposed opposite the first end along a longitudinal axis of the golfshaft. The golf shaft may define one or more internal cavities extendingalong the longitudinal axis. The golf shaft may have an overall lengthfrom the first end to the second end, and an outer diameter of the golfshaft may continuously decrease from the first end to the second end.

In another aspect, a golf shaft is provided. In one embodiment, the golfshaft may include a first end and a second end disposed opposite thefirst end along a longitudinal axis of the golf shaft. The golf shaftmay be formed of one or more metals or metal alloys, and the golf shaftmay define one or more internal cavities extending along thelongitudinal axis. The golf shaft may have an overall length from thefirst end to the second end, and an outer diameter of the golf shaft maycontinuously decrease from the first end to the second end.

In some embodiments, the outer diameter of the golf shaft maycontinuously decrease in a linear manner from the first end to thesecond end. In some embodiments, the outer diameter of the golf shaftmay continuously decrease in a non-linear manner from the first end tothe second end. In some embodiments, the golf shaft may include a firstshaft portion disposed between the first end and the second end, and asecond shaft portion disposed between the first end and the second end.The outer diameter of the golf shaft may continuously decrease at anincreasing rate along the first shaft portion in a direction from thefirst end toward the second end, and the outer diameter of the golfshaft may continuously decrease at a decreasing rate along the secondshaft portion in the direction from the first end toward the second end.In some embodiments, an inner diameter of the golf shaft maycontinuously increase along the first shaft portion in the directionfrom the first end toward the second end, and the inner diameter of thegolf shaft may continuously decrease along the second shaft portion inthe direction from the first end toward the second end. In someembodiments, the inner diameter of the golf shaft may continuouslyincrease in a linear manner along the first shaft portion in thedirection from the first end toward the second end. In some embodiments,the inner diameter of the golf shaft may continuously increase in anon-linear manner along the first shaft portion in the direction fromthe first end toward the second end. In some embodiments, the innerdiameter of the golf shaft may continuously decrease in a linear manneralong the second shaft portion in the direction from the first endtoward the second end. In some embodiments, the inner diameter of thegolf shaft may continuously decrease in a non-linear manner along thesecond shaft portion in the direction from the first end toward thesecond end. In some embodiments, the golf shaft also may include a thirdshaft portion disposed between the first end and the second end, and theinner diameter of the golf shaft may be constant along the third shaftportion. In some embodiments, a wall thickness of the golf shaft maycontinuously vary along at least a majority of the overall length. Insome embodiments, the wall thickness of the golf shaft may continuouslyvary along an entirety of the overall length. In some embodiments, thewall thickness of the golf shaft may be constant along a minority of theoverall length. In some embodiments, the one or more metals or metalalloys may include at least one of: steel, a steel alloy, titanium, atitanium alloy, aluminum, or an aluminum alloy.

In still another aspect, a golf club is provided. In one embodiment, thegolf club may include a golf shaft, a grip, and a clubhead. The golfshaft may include a first end, a second end disposed opposite the firstend along a longitudinal axis of the golf shaft, a grip sectionextending from the first end toward the second end, and a clubheadsection extending from the second end toward the first end. The golfshaft may be formed of one or more metals or metal alloys, and the golfshaft may define one or more internal cavities extending along thelongitudinal axis. The golf shaft may have an overall length from thefirst end to the second end, and an outer diameter of the golf shaft maycontinuously decrease from the first end to the second end. The grip maybe coupled to the grip section, and the clubhead may be coupled to theclubhead section.

In one aspect, a method for manufacturing a golf shaft is provided. Inone embodiment, the method may include receiving a CAD modelcorresponding to the golf shaft, and forming, based at least in part onthe CAD model, the golf shaft using one or more additive manufacturingtechniques. The golf shaft may include a first end, a second enddisposed opposite the first end along a longitudinal axis of the golfshaft, and one or more shaft portions disposed between the first end andthe second end. The golf shaft may define one or more internal cavitiesextending along the longitudinal axis. The golf shaft may have anoverall length from the first end to the second end, and an outerdiameter of the golf shaft may continuously vary in a non-linear manneralong each of the one or more shaft portions.

In another aspect, a golf shaft is provided. In one embodiment, the golfshaft may include a first end, a second end disposed opposite the firstend along a longitudinal axis of the golf shaft, and one or more shaftportions disposed between the first end and the second end. The golfshaft may define one or more internal cavities extending along thelongitudinal axis. The golf shaft may have an overall length from thefirst end to the second end, and an outer diameter of the golf shaft maycontinuously vary in a non-linear manner along each of the one or moreshaft portions.

In some embodiments, the outer diameter of the golf shaft maycontinuously decrease in a non-linear manner along each of the one ormore shaft portions in a direction from the first end toward the secondend. In some embodiments, the outer diameter of the golf shaft maycontinuously decrease at an increasing rate along each of the one ormore shaft portions in the direction from the first end toward thesecond end. In some embodiments, the outer diameter of the golf shaftmay continuously decrease at a decreasing rate along each of the one ormore shaft portions in the direction from the first end toward thesecond end. In some embodiments, the outer diameter of the golf shaftmay continuously increase in a non-linear manner along each of the oneor more shaft portions in a direction from the first end toward thesecond end. In some embodiments, the outer diameter of the golf shaftmay continuously increase at an increasing rate along each of the one ormore shaft portions in the direction from the first end toward thesecond end. In some embodiments, the outer diameter of the golf shaftmay continuously increase at a decreasing rate along each of the one ormore shaft portions in the direction from the first end toward thesecond end. In some embodiments, the one or more shaft portions mayinclude a first shaft portion disposed between the first end and thesecond end, and a second shaft portion disposed between the first endand the second end. The outer diameter of the golf shaft maycontinuously decrease in a non-linear manner along the first shaftportion in a direction from the first end toward the second end, and theouter diameter of the golf shaft may continuously increase in anon-linear manner along the second shaft portion in the direction fromthe first end toward the second end. In some embodiments, an innerdiameter of the golf shaft may continuously vary in a non-linear manneralong each of the one or more shaft portions. In some embodiments, thegolf shaft may be formed of one or more metals or metal alloys. In someembodiments, the one or more metals or metal alloys may include at leastone of: steel, a steel alloy, titanium, a titanium alloy, aluminum, oran aluminum alloy.

In still another aspect, a golf club is provided. In one embodiment, thegolf club may include a golf shaft, a grip, and a clubhead. The golfshaft may include a first end, a second end disposed opposite the firstend along a longitudinal axis of the golf shaft, one or more shaftportions disposed between the first end and the second end, a gripsection extending from the first end toward the second end, and aclubhead section extending from the second end toward the first end. Thegolf shaft may define one or more internal cavities extending along thelongitudinal axis. The golf shaft may have an overall length from thefirst end to the second end, and an outer diameter of the golf shaft maycontinuously vary in a non-linear manner along each of the one or moreshaft portions. The grip may be coupled to the grip section, and theclubhead may be coupled to the clubhead section.

In one aspect, a method for manufacturing a golf shaft is provided. Inone embodiment, the method may include receiving a CAD modelcorresponding to the golf shaft, and forming, based at least in part onthe CAD model, the golf shaft using one or more additive manufacturingtechniques. The golf shaft may include a first end, a second enddisposed opposite the first end along a longitudinal axis of the golfshaft, and one or more shaft portions disposed between the first end andthe second end. The golf shaft may define one or more internal cavitiesextending along the longitudinal axis. The golf shaft may have anoverall length from the first end to the second end, and an innerdiameter of the golf shaft may continuously vary in a non-linear manneralong each of the one or more shaft portions.

In another aspect, a golf shaft is provided. In one embodiment, the golfshaft may include a first end, a second end disposed opposite the firstend along a longitudinal axis of the golf shaft, and one or more shaftportions disposed between the first end and the second end. The golfshaft may define one or more internal cavities extending along thelongitudinal axis. The golf shaft may have an overall length from thefirst end to the second end, and an inner diameter of the golf shaft maycontinuously vary in a non-linear manner along each of the one or moreshaft portions.

In some embodiments, the inner diameter of the golf shaft maycontinuously decrease in a non-linear manner along each of the one ormore shaft portions in a direction from the first end toward the secondend. In some embodiments, the inner diameter of the golf shaft maycontinuously decrease at an increasing rate along each of the one ormore shaft portions in the direction from the first end toward thesecond end. In some embodiments, the inner diameter of the golf shaftmay continuously decrease at a decreasing rate along each of the one ormore shaft portions in the direction from the first end toward thesecond end. In some embodiments, the inner diameter of the golf shaftmay continuously increase in a non-linear manner along each of the oneor more shaft portions in a direction from the first end toward thesecond end. In some embodiments, the inner diameter of the golf shaftmay continuously increase at an increasing rate along each of the one ormore shaft portions in the direction from the first end toward thesecond end. In some embodiments, the inner diameter of the golf shaftmay continuously increase at a decreasing rate along each of the one ormore shaft portions in the direction from the first end toward thesecond end. In some embodiments, the one or more shaft portions mayinclude a first shaft portion disposed between the first end and thesecond end, and a second shaft portion disposed between the first endand the second end. The inner diameter of the golf shaft maycontinuously decrease in a non-linear manner along the first shaftportion in a direction from the first end toward the second end, and theinner diameter of the golf shaft may continuously increase in anon-linear manner along the second shaft portion in the direction fromthe first end toward the second end. In some embodiments, an outerdiameter of the golf shaft may continuously vary in a non-linear manneralong each of the one or more shaft portions. In some embodiments, thegolf shaft may be formed of one or more metals or metal alloys. In someembodiments, the one or more metals or metal alloys may include at leastone of: steel, a steel alloy, titanium, a titanium alloy, aluminum, oran aluminum alloy.

In still another aspect, a golf club is provided. In one embodiment, thegolf club may include a golf shaft, a grip, and a clubhead. The golfshaft may include a first end, a second end disposed opposite the firstend along a longitudinal axis of the golf shaft, one or more shaftportions disposed between the first end and the second end, a gripsection extending from the first end toward the second end, and aclubhead section extending from the second end toward the first end. Thegolf shaft may define one or more internal cavities extending along thelongitudinal axis. The golf shaft may have an overall length from thefirst end to the second end, and an inner diameter of the golf shaft maycontinuously vary in a non-linear manner along each of the one or moreshaft portions. The grip may be coupled to the grip section, and theclubhead may be coupled to the clubhead section.

In one aspect, a method for manufacturing a golf shaft is provided. Inone embodiment, the method may include receiving a CAD modelcorresponding to the golf shaft, and forming, based at least in part onthe CAD model, the golf shaft using one or more additive manufacturingtechniques. The golf shaft may include a first end, a second enddisposed opposite the first end along a longitudinal axis of the golfshaft, a shaft body extending from the first end to the second end, andan internal lattice structure. The golf shaft may have an overall lengthfrom the first end to the second end. The shaft body may define aninternal cavity extending along the longitudinal axis. The internallattice structure may be disposed within the internal cavity.

In another aspect, a golf shaft is provided. In one embodiment, the golfshaft may include a first end, a second end disposed opposite the firstend along a longitudinal axis of the golf shaft, a shaft body extendingfrom the first end to the second end, and an internal lattice structure.The golf shaft may have an overall length from the first end to thesecond end. The shaft body may define an internal cavity extending alongthe longitudinal axis. The internal lattice structure may be disposedwithin the internal cavity. The golf shaft may be formed of one or moremetals or metal alloys.

In some embodiments, the internal lattice structure may define aplurality of openings each having a polygonal shape. In someembodiments, the internal lattice structure may extend along at leastpart of a length of the internal cavity. In some embodiments, theinternal lattice structure may extend along an entirety of a length ofthe internal cavity. In some embodiments, the internal cavity may extendfrom the first end to the second end, and the internal lattice structuremay extend from the first end to the second end. In some embodiments,the internal cavity may extend from the first end toward the second endand be spaced apart from the second end, and the internal latticestructure may extend from the first end toward the second end and bespaced apart from the second end. In some embodiments, the internalcavity may extend from the second end toward the first end and be spacedapart from the first end, and the internal lattice structure may extendfrom the second end toward the first end and be spaced apart from thefirst end. In some embodiments, the internal cavity may be spaced apartfrom each of the first end and the second end, and the internal latticestructure may extend along an entirety of a length of the internalcavity. In some embodiments, the shaft body and the internal latticestructure may be integrally formed with one another. In someembodiments, a wall thickness of the shaft body may vary along theoverall length. In some embodiments, a wall thickness of the shaft bodymay continuously vary along at least a majority of the overall length.In some embodiments, an outer diameter of the shaft body may vary alongthe overall length. In some embodiments, an outer diameter of the shaftbody may continuously vary along at least a majority of the overalllength. In some embodiments, an inner diameter of the shaft body mayvary along the overall length. In some embodiments, an outer diameter ofthe shaft body may continuously vary along at least a majority of theoverall length. In some embodiments, the one or more metals or metalalloys may include at least one of: steel, a steel alloy, titanium, atitanium alloy, aluminum, or an aluminum alloy.

In still another aspect, a golf club is provided. In one embodiment, thegolf club may include a golf shaft, a grip, and a clubhead. The golfshaft may include a first end, a second end disposed opposite the firstend along a longitudinal axis of the golf shaft, a shaft body extendingfrom the first end to the second end, and an internal lattice structure.The golf shaft may have an overall length from the first end to thesecond end. The shaft body may define an internal cavity extending alongthe longitudinal axis. The shaft body may include a grip sectionextending from the first end toward the second end, and a clubheadsection extending from the second end toward the first end. The internallattice structure may be disposed within the internal cavity. The golfshaft may be formed of one or more metals or metal alloys. The grip maybe coupled to the grip section, and the clubhead may be coupled to theclubhead section.

In one aspect, a method for manufacturing a golf shaft is provided. Inone embodiment, the method may include receiving a CAD modelcorresponding to the golf shaft, and forming, based at least in part onthe CAD model, the golf shaft using one or more additive manufacturingtechniques. The golf shaft may include a first end, a second enddisposed opposite the first end along a longitudinal axis of the golfshaft, a shaft body extending from the first end to the second end andhaving an outer surface, and an external geometric structure disposedalong the outer surface. The golf shaft may have an overall length fromthe first end to the second end. The shaft body may define an internalcavity extending along the longitudinal axis. The external geometricstructure may have a pattern of geometric shapes.

In another aspect, a golf shaft is provided. In one embodiment, the golfshaft may include a first end, a second end disposed opposite the firstend along a longitudinal axis of the golf shaft, a shaft body extendingfrom the first end to the second end and having an outer surface, and anexternal geometric structure disposed along the outer surface. The golfshaft may have an overall length from the first end to the second end.The shaft body may define an internal cavity extending along thelongitudinal axis. The external geometric structure may have a patternof geometric shapes. The golf shaft may be formed of one or more metalsor metal alloys.

In some embodiments, the pattern of geometric shapes may be a repeatingpattern. In some embodiments, the pattern of geometric shapes may be anon-repeating pattern. In some embodiments, the external geometricstructure may have a repeating pattern of polygonal shapes. In someembodiments, the external geometric structure may include one or morehelixes centered on the longitudinal axis. In some embodiments, theshaft body may include a grip section extending from the first endtoward the second end and configured to receive a grip thereon, aclubhead section extending from the second end toward the first end andconfigured to receive a clubhead thereon, and an intermediate sectionextending from the grip section to the clubhead section. In someembodiments, the external geometric structure may extend along at leastpart of a length of the intermediate section. In some embodiments, theexternal geometric structure may extend along at least a majority of thelength of the intermediate section. In some embodiments, the externalgeometric structure may extend along an entirety of the length of theintermediate section. In some embodiments, the internal cavity mayextend from the first end to the second end. In some embodiments, theinternal cavity may extend from the first end toward the second end andbe spaced apart from the second end. In some embodiments, the internalcavity may extend from the second end toward the first end and be spacedapart from the first end. In some embodiments, the internal cavity maybe spaced apart from each of the first end and the second end. In someembodiments, the shaft body and the external geometric structure may beintegrally formed with one another. In some embodiments, a wallthickness of the shaft body may vary along the overall length. In someembodiments, a wall thickness of the shaft body may continuously varyalong at least a majority of the overall length. In some embodiments, anouter diameter of the shaft body may vary along the overall length. Insome embodiments, an outer diameter of the shaft body may continuouslyvary along at least a majority of the overall length. In someembodiments, an inner diameter of the shaft body may vary along theoverall length. In some embodiments, an outer diameter of the shaft bodymay continuously vary along at least a majority of the overall length.In some embodiments, the one or more metals or metal alloys may includeat least one of: steel, a steel alloy, titanium, a titanium alloy,aluminum, or an aluminum alloy.

In still another aspect, a golf club is provided. In one embodiment, thegolf club may include a golf shaft, a grip, and a clubhead. The golfshaft may include a first end, a second end disposed opposite the firstend along a longitudinal axis of the golf shaft, a shaft body extendingfrom the first end to the second end and having an outer surface, and anexternal geometric structure disposed along the outer surface. The golfshaft may have an overall length from the first end to the second end.The shaft body may define an internal cavity extending along thelongitudinal axis. The shaft body may include a grip section extendingfrom the first end toward the second end, a clubhead section extendingfrom the second end toward the first end, and an intermediate sectionextending from the grip section to the clubhead section. The externalgeometric structure may be disposed along the intermediate section, andthe external geometric structure may have a pattern of geometric shapes.The golf shaft may be formed of one or more metals or metal alloys. Thegrip may be coupled to the grip section, and the clubhead may be coupledto the clubhead section.

In one aspect, a method for manufacturing a golf shaft is provided. Inone embodiment, the method may include receiving a CAD modelcorresponding to the golf shaft, and forming, based at least in part onthe CAD model, the golf shaft using one or more additive manufacturingtechniques. The golf shaft may include a first end, a second enddisposed opposite the first end along a longitudinal axis of the golfshaft, and an external geometric structure extending along thelongitudinal axis. The golf shaft may have an overall length from thefirst end to the second end. The external geometric structure may have apattern of geometric shapes, and the golf shaft may be devoid of anythin-walled cylindrical segments.

In another aspect, a golf shaft is provided. In one embodiment, the golfshaft may include a first end, a second end disposed opposite the firstend along a longitudinal axis of the golf shaft, and an externalgeometric structure extending along the longitudinal axis. The golfshaft may have an overall length from the first end to the second end.The shaft body may define an internal cavity extending along thelongitudinal axis. The external geometric structure may have a patternof geometric shapes. The golf shaft may be formed of one or more metalsor metal alloys, and at least a portion of the golf shaft may be devoidof any thin-walled cylindrical segments.

In some embodiments, the pattern of geometric shapes may be a repeatingpattern. In some embodiments, the pattern of geometric shapes may be anon-repeating pattern. In some embodiments, the external geometricstructure may have a repeating pattern of polygonal shapes. In someembodiments, the external geometric structure may include one or morehelixes centered on the longitudinal axis. In some embodiments, theshaft body may include a grip section extending from the first endtoward the second end and configured to receive a grip thereon, aclubhead section extending from the second end toward the first end andconfigured to receive a clubhead thereon, and an intermediate sectionextending from the grip section to the clubhead section. In someembodiments, the external geometric structure may extend along at leastpart of a length of the intermediate section. In some embodiments, theexternal geometric structure may extend along at least a majority of thelength of the intermediate section. In some embodiments, the externalgeometric structure may extend along an entirety of the length of theintermediate section. In some embodiments, the one or more metals ormetal alloys may include at least one of: steel, a steel alloy,titanium, a titanium alloy, aluminum, or an aluminum alloy.

In still another aspect, a golf club is provided. In one embodiment, thegolf club may include a golf shaft, a grip, and a clubhead. The golfshaft may include a first end, a second end disposed opposite the firstend along a longitudinal axis of the golf shaft, a grip sectionextending from the first end toward the second end, a clubhead sectionextending from the second end toward the first end, an intermediatesection extending from the grip section to the clubhead section, and anexternal geometric structure extending along the longitudinal axis. Thegolf shaft may have an overall length from the first end to the secondend. The external geometric structure may have a pattern of geometricshapes. The golf shaft may be formed of one or more metals or metalalloys, and the golf shaft may be devoid of any thin-walled cylindricalsegments. The grip may be coupled to the grip section, and the clubheadmay be coupled to the clubhead section.

These and other aspects and improvements of the present disclosure willbecome apparent to one of ordinary skill in the art upon review of thefollowing detailed description when taken in conjunction with theseveral drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a plan view of an example golf club in accordance with one ormore embodiments of the disclosure, the golf club including a golfshaft, a grip, and a clubhead.

FIG. 1B is a detailed cross-sectional plan view of a region of the golfshaft of the golf club of FIG. 1A, with the cross-section taken alongplane 1B-1B of FIG. 1A, showing an internal cavity and varying wallthickness of the golf shaft.

FIG. 1C is a detailed cross-sectional end view of a region of the golfshaft of the golf club of FIG. 1A, with the cross-section taken alongplane 1C-1C of FIG. 1A.

FIG. 2A is a plan view of an example golf shaft as may be used as a partof the golf club of FIG. 1 in accordance with one or more embodiments ofthe disclosure.

FIG. 2B is a cross-sectional plan view of the golf shaft of FIG. 2A,with the cross-section taken along plane 2B-2B of FIG. 2A, showing aninternal cavity and varying wall thickness of the golf shaft.

FIG. 3A is a plan view of an example golf shaft as may be used as a partof the golf club of FIG. 1 in accordance with one or more embodiments ofthe disclosure.

FIG. 3B is a cross-sectional plan view of the golf shaft of FIG. 3A,with the cross-section taken along plane 3B-3B of FIG. 3A, showing aninternal cavity and varying wall thickness of the golf shaft.

FIG. 4A is a plan view of an example golf shaft as may be used as a partof the golf club of FIG. 1 in accordance with one or more embodiments ofthe disclosure.

FIG. 4B is a cross-sectional plan view of the golf shaft of FIG. 4A,with the cross-section taken along plane 4B-4B of FIG. 4A, showing aninternal cavity of the golf shaft.

FIG. 4C is a detailed cross-sectional plan view of a first region of thegolf shaft of FIG. 4A, similar to the cross-section of FIG. 4B, showingvarying wall thickness of the golf shaft along the first region.

FIG. 4D is a detailed cross-sectional plan view of a second region ofthe golf shaft of FIG. 4A, similar to the cross-section of FIG. 4B,showing varying wall thickness of the golf shaft along the secondregion.

FIG. 4E is a detailed cross-sectional plan view of a third region of thegolf shaft of FIG. 4A, similar to the cross-section of FIG. 4B, showingvarying wall thickness of the golf shaft along the third region.

FIG. 4F is a detailed cross-sectional plan view of a fourth region ofthe golf shaft of FIG. 4A, similar to the cross-section of FIG. 4B,showing varying wall thickness of the golf shaft along the fourthregion.

FIG. 4G is a detailed cross-sectional plan view of a fifth region of thegolf shaft of FIG. 4A, similar to the cross-section of FIG. 4B, showingvarying wall thickness of the golf shaft along the fifth region.

FIG. 5A is a plan view of an example golf shaft as may be used as a partof the golf club of FIG. 1 in accordance with one or more embodiments ofthe disclosure.

FIG. 5B is a cross-sectional plan view of the golf shaft of FIG. 5A,with the cross-section taken along plane 5B-5B of FIG. 5A, showing aninternal cavity and an internal lattice structure of the golf shaft.

FIG. 6 is a plan view of a portion of an example golf shaft as may beused as a part of the golf club of FIG. 1 in accordance with one or moreembodiments of the disclosure, showing an external geometric structureof the golf shaft.

FIG. 7 is a plan view of a portion of an example golf shaft as may beused as a part of the golf club of FIG. 1 in accordance with one or moreembodiments of the disclosure, showing an external geometric structureof the golf shaft.

FIG. 8 is a plan view of a portion of an example golf shaft as may beused as a part of the golf club of FIG. 1 in accordance with one or moreembodiments of the disclosure, showing an external geometric structureof the golf shaft.

FIG. 9 is a plan view of a portion of an example golf shaft as may beused as a part of the golf club of FIG. 1 in accordance with one or moreembodiments of the disclosure, showing an external geometric structureof the golf shaft.

FIG. 10 is a plan view of a portion of an example golf shaft as may beused as a part of the golf club of FIG. 1 in accordance with one or moreembodiments of the disclosure, showing an external geometric structureof the golf shaft.

The detailed description is set forth with reference to the accompanyingdrawings. The drawings are provided for purposes of illustration onlyand merely depict example embodiments of the disclosure. The drawingsare provided to facilitate understanding of the disclosure and shall notbe deemed to limit the breadth, scope, or applicability of thedisclosure. The use of the same reference numerals indicates similar,but not necessarily the same or identical components. Differentreference numerals may be used to identify similar components. Variousembodiments may utilize elements or components other than thoseillustrated in the drawings, and some elements and/or components may notbe present in various embodiments. The use of singular terminology todescribe a component or element may, depending on the context, encompassa plural number of such components or elements and vice versa.

DETAILED DESCRIPTION OF THE DISCLOSURE

In the following description, specific details are set forth describingsome embodiments consistent with the present disclosure. Numerousspecific details are set forth in order to provide a thoroughunderstanding of the embodiments. It will be apparent, however, to oneskilled in the art that some embodiments may be practiced without someor all of these specific details. The specific embodiments disclosedherein are meant to be illustrative but not limiting. One skilled in theart may realize other elements that, although not specifically describedhere, are within the scope and the spirit of this disclosure. Inaddition, to avoid unnecessary repetition, one or more features shownand described in association with one embodiment may be incorporatedinto other embodiments unless specifically described otherwise or if theone or more features would make an embodiment non-functional. In someinstances, well known methods, procedures, and/or components have notbeen described in detail so as not to unnecessarily obscure aspects ofthe embodiments.

Overview

Embodiments of golf shafts having a varying outer diameter, innerdiameter, and/or wall thickness and related methods for manufacturinggolf shafts having a varying outer diameter, inner diameter, and/or wallthickness using additive manufacturing are provided herein. According tothe techniques described herein, a golf shaft may be customized for aparticular user by varying the shaft's outer diameter, inner diameter,and/or wall thickness along the length of the shaft in a manner thatprovides an optimal stiffness profile for the user. Additionally, golfshafts having a varying outer diameter, inner diameter, and/or wallthickness according to the present disclosure may be mass produced andprovided in a wide variety of shaft stiffness bins, such as bins foreach 1 mph increment of swing speed. Although the disclosed golf shaftsmay be manufactured by various methods, the use of additivemanufacturing techniques may be particularly advantageous forfabricating the shafts, as described below.

The golf shafts provided herein may include a first end and a second enddisposed opposite one another along a longitudinal axis of the shaft anddefining an overall length of the shaft. The golf shaft may define oneor more internal cavities extending along the longitudinal axis. Asdescribed herein, an outer diameter, an inner diameter, and/or a wallthickness of the golf shaft may continuously vary along one or moreportions of the overall length. According to various embodiments, thewall thickness may continuously vary along at least 5%, at least 10%, atleast 20%, at least 30%, at least 40%, at least 50%, at least 60%, atleast 70%, at least 80%, or at least 90% of the overall length. In someembodiments, the wall thickness may continuously vary along at least amajority of the overall length. In some embodiments, the wall thicknessmay continuously vary along an entirety of the overall length. In someembodiments, the wall thickness may continuously vary along a continuousportion of the shaft having a length that is greater than 50% of theoverall length. In some embodiments, the wall thickness may be constantalong a minority of the overall length. As described herein, the wallthickness may continuously decrease along one or more portions of theshaft in a direction from the first end toward the second end and/or thewall thickness may continuously increase along one or more portions ofthe shaft in the direction from the first end toward the second end. Insome embodiments, the wall thickness may continuously increase orcontinuously decrease in a linear manner along one or more portions ofthe shaft. In some embodiments, the wall thickness may continuouslyincrease or continuously decrease in a non-linear manner along one ormore portions of the shaft. In this manner, the wall thickness maycontinuously decrease or continuously increase at a varying rate.According to various embodiments, the wall thickness may be continuouslyvaried over a particular portion of the shaft by continuously varying anouter diameter of the shaft, an inner diameter of the shaft, or both theouter diameter and the inner diameter along the shaft portion. Variouscombinations of one or more shaft portions having acontinuously-decreasing wall thickness, one or more shaft portionshaving a continuously-increasing wall thickness, and one or more shaftportions having a constant wall thickness may be used to provide adesired stiffness profile of the shaft. Ultimately, a particularconfiguration of varying wall thickness of a golf shaft may be selectedto provide an optimal stiffness profile for a particular user or for aparticular subset of users having closely-similar swing speeds.

The use of additive manufacturing to fabricate golf shaftsadvantageously may provide the ability to continuously alter thestiffness profile along the length of a shaft instead of in steppedincrements according to traditional manufacturing techniques. Althoughvarious types of additive manufacturing techniques may be used toproduce the golf shafts described herein, selective laser melting (SLM)and direct metal laser sintering (DMLS) are two techniques that may beparticularly well suited for manufacturing the shafts. By utilizing oneor more additive manufacturing techniques, such as SLM or DMLS, thestiffness profile of a golf shaft may be controlled by varying the outerdiameter, the inner diameter, and/or the wall thickness along the shaft.Meanwhile, the outer dimensions of end portions of the golf shaft may beselected to correspond to the outer dimensions of conventional golfshafts, thereby allowing the golf shaft to suitably interface withcommon grips and clubheads. By using additive manufacturing, thestiffness profile of a golf shaft may be optimized for each user'sdifferent swing speed and tempo, resulting in increased distance andimproved accuracy for each user. For users who do not want to pay for acustom fitting, golf shafts may be mass produced in a wide variety ofbins for different swing speeds. For example, different golf shafts maybe provided in shaft stiffness bins having 1 mph increments instead ofthe significantly larger increments used in the conventional binapproach. In contrast to traditional methods for manufacturing golfshafts, additive manufacturing techniques do not require tooling andthus allow for each shaft in a build to be unique. Therefore, by usingadditive manufacturing, the cost to build 100 shafts for a single swingspeed and the cost to build 100 shafts for 100 different swing speedswould be the same. As described herein, additive manufacturing also mayenable fabrication of golf shafts having other complex features thatwould be challenging or impossible to form using conventionalmanufacturing methods. For example, a golf shaft may include an internallattice structure disposed within a cavity of the shaft, theconfiguration and extent of which may be selected to vary the stiffnessprofile of the shaft. As another example, an external geometricstructure having a pattern of geometric shapes may be provided along anouter surface of a golf shaft, which may provide aesthetic appeal and/ormay be configured to increase performance characteristics of the shaft.Such an external geometric structure may include a pattern of polygonalshapes, a honeycomb structure, one or more helixes, or other complexgeometric forms. The pattern of geometric shapes may be repeating ornon-repeating in different embodiments. Further, other types of externalstructures having irregular or non-geometric forms also may be providedalong an outer surface of a golf shape for aesthetic appeal and/orincreased performance characteristics. The formation of such externalstructures, which may not be feasible or practical using traditionalmanufacturing techniques, may be readily achieved using additivemanufacturing techniques.

Still other benefits and advantages of the golf shafts and methods formanufacturing golf shafts provided herein over existing technology willbe appreciated by those of ordinary skill in the art from the followingdescription and the appended drawings.

Example Embodiments of Golf Clubs and Golf Shafts

Referring now to FIGS. 1A-1C, an example golf club 100 (which also maybe referred to as simply a “club”) is depicted. In some embodiments, asshown, the golf club 100 may be an iron, although other configurationsof the club 100 as a wedge, a hybrid, a driver, a wood, or a putter maybe used in other embodiments. The golf club 100 may include a golf shaft110 (which also may be referred to as simply a “shaft”), a grip 150, anda clubhead 160. In some embodiments, the grip 150 and the clubhead 160each may have a conventional configuration and may be coupled to theshaft 110 in a conventional manner. It will be appreciated that variousconfigurations of the clubhead 160 may be used, depending on whether thegolf club 100 is provided as an iron, a wedge, a hybrid, a driver, awood, or a putter.

As shown, the golf shaft 110 may be formed as an elongated structurehaving a longitudinal axis A_(L). The shaft 110 may have a first end 112(which also may be referred to as a “butt end” or a “grip end”) and asecond end 114 (which also may be referred to as a “tip end” or a“clubhead end”) disposed opposite one another along the longitudinalaxis A_(L) of the shaft 110. As shown, the shaft 110 may have an overalllength L_(O) from the first end 112 to the second end 114. The shaft 110may include a first end section 122 (which also may be referred to as a“butt end section” or a “grip end section”), a second end section 124(which also may be referred to as a “tip end section” or a “clubhead endsection”), and an intermediate section 126 extending from the first endsection 122 to the second end section 124. As shown, the first endsection 122 may be configured to receive the grip 150 thereon, and thesecond end section 124 may be configured to receive the clubhead 160thereon. In this manner, upon assembly of the golf club 100, the grip150 may cover and be coupled to the first end section 122, and theclubhead 160 may cover and be coupled to the second end section 124,while the intermediate section 126 may remain exposed and not be coveredby the grip 150 or the clubhead 160.

The golf shaft 110 may define one or more internal cavities 130 (each ofwhich also may be referred to as an “internal opening” or “opening,” an“internal bore” or “bore,” or simply a “cavity”) extending along thelongitudinal axis A_(L) of the shaft 110. In this manner, the shaft 110may have a tubular shape along at least a portion of the shaft 110. Insome embodiments, the shaft 110 may define a single internal cavity 130.In some embodiments, the cavity 130 may extend from the first end 112 tothe second end 114. In this manner, the cavity 130 may extend along theentire overall length L_(O) of the shaft 110, with the first end 112 andthe second end 114 being open. In some embodiments, the cavity 130 mayextend from the first end 112 toward the second end 114 and be spacedapart from the second end 114. In other words, the cavity 130 may beginat the first end 112 and terminate at a location spaced apart from thesecond end 114. In this manner, the cavity 130 may extend along only aportion of the overall length L_(O) of the shaft 110, with the first end112 being open and the second end 114 being closed. In some embodiments,the cavity 130 may extend from the second end 114 toward the first end112 and be spaced apart from the first end 112. In other words, thecavity 130 may begin at the second end 114 and terminate at a locationspaced apart from the first end 112. In this manner, the cavity 130 mayextend along only a portion of the overall length L_(O) of the shaft110, with the second end 114 being open and the first end 112 beingclosed. In some embodiments, the cavity 130 may be spaced apart fromeach of the first end 112 and the second end 114. In other words, thecavity 130 may begin at a location spaced apart from the first end 112and terminate at a location spaced apart from the second end 114. Inthis manner, the cavity 130 may extend along only a portion of theoverall length L_(O) of the shaft 110, with each of the first end 112and the second end 114 being closed. In some embodiments, the golf shaft110 may define two or more internal cavities 130 that are not incommunication with one another. In other words, the shaft 110 mayinclude a portion having a solid cross section (taken perpendicular tothe longitudinal axis A_(L) of the shaft 110) disposed between aconsecutive pair of the cavities 130. Various configurations of one ormore internal cavities 130 may be used in different embodiments.

The golf shaft 110 may have an outer surface 132 (which also may bereferred to as an “external surface”) and an inner surface 134 (whichalso may be referred to as an “internal surface”). As shown in FIGS. 1Band 1C, the inner surface 134 may define the cavity 130. In someembodiments, as shown, each of the outer surface 132 and the innersurface 134 may have a circular cross-sectional shape (takenperpendicular to the longitudinal axis A_(L) of the shaft 110). In thismanner, the shaft 110 may have an outer diameter OD, an inner diameterID, and a wall thickness T_(W), as shown in FIG. 1B.

The outer diameter OD of the shaft 110 may continuously vary along oneor more portions of the overall length L_(O). According to variousembodiments, the outer diameter OD may continuously vary along at least5%, at least 10%, at least 20%, at least 30%, at least 40%, at least50%, at least 60%, at least 70%, at least 80%, or at least 90% of theoverall length L_(O). In some embodiments, the outer diameter OD maycontinuously vary along at least a majority (i.e., greater than 50%) ofthe overall length L_(O). In some embodiments, the outer diameter OD maycontinuously vary along only a minority (i.e., less than 50%) of theoverall length L_(O). In some embodiments, the outer diameter OD maycontinuously vary along an entirety of the overall length L_(O).According to various embodiments, the outer diameter OD may continuouslyvary along a continuous portion of the shaft 110 having a length that isgreater than 5%, greater than 10%, greater than 20%, greater than 30%,greater than 40%, greater than 50%, greater than 60%, greater than 70%,greater than 80%, or greater than 90% of the overall length L_(O). Insome embodiments, the outer diameter OD may be constant along one ormore portions of the overall length L_(O). According to variousembodiments, the outer diameter OD may be constant along at least 5%, atleast 10%, at least 20%, at least 30%, at least 40%, at least 50%, atleast 60%, at least 70%, at least 80%, or at least 90% of the overalllength L_(O). In some embodiments, the outer diameter OD may be constantalong at least a majority (i.e., greater than 50%) of the overall lengthL_(O). In some embodiments, the outer diameter OD may be constant alongonly a minority (i.e., less than 50%) of the overall length L_(O). Insome embodiments, the outer diameter OD may be constant along anentirety of the overall length L_(O). According to various embodiments,the outer diameter OD may be constant along a continuous portion of theshaft 110 having a length that is greater than 5%, greater than 10%,greater than 20%, greater than 30%, greater than 40%, greater than 50%,greater than 60%, greater than 70%, greater than 80%, or greater than90% of the overall length L_(O).

The outer diameter OD may continuously decrease along one or moreportions of the shaft 110 in a direction from the first end 112 towardthe second end 114 and/or the outer diameter OD may continuouslyincrease along one or more portions of the shaft 110 in the directionfrom the first end 112 toward the second end 114. In some embodiments,the outer diameter OD may continuously increase or continuously decreasein a linear manner along one or more portions of the shaft 110. In someembodiments, the outer diameter OD may continuously increase orcontinuously decrease in a non-linear manner along one or more portionsof the shaft 110. In this manner, the outer diameter OD may continuouslydecrease or continuously increase at a varying rate. Variouscombinations of one or more shaft portions having acontinuously-decreasing outer diameter OD, one or more shaft portionshaving a continuously-increasing outer diameter OD, and one or moreshaft portions having a constant outer diameter OD may be used toprovide a desired stiffness profile of the shaft 110.

The inner diameter ID of the shaft 110 may continuously vary along oneor more portions of the overall length L_(O). According to variousembodiments, the inner diameter ID may continuously vary along at least5%, at least 10%, at least 20%, at least 30%, at least 40%, at least50%, at least 60%, at least 70%, at least 80%, or at least 90% of theoverall length L_(O). In some embodiments, the inner diameter ID maycontinuously vary along at least a majority (i.e., greater than 50%) ofthe overall length L_(O). In some embodiments, the inner diameter ID maycontinuously vary along only a minority (i.e., less than 50%) of theoverall length L_(O). In some embodiments, the inner diameter ID maycontinuously vary along an entirety of the overall length L_(O).According to various embodiments, the inner diameter ID may continuouslyvary along a continuous portion of the shaft 110 having a length that isgreater than 5%, greater than 10%, greater than 20%, greater than 30%,greater than 40%, greater than 50%, greater than 60%, greater than 70%,greater than 80%, or greater than 90% of the overall length L_(O). Insome embodiments, the inner diameter ID may be constant along one ormore portions of the overall length L_(O). According to variousembodiments, the inner diameter ID may be constant along at least 5%, atleast 10%, at least 20%, at least 30%, at least 40%, at least 50%, atleast 60%, at least 70%, at least 80%, or at least 90% of the overalllength L_(O). In some embodiments, the inner diameter ID may be constantalong at least a majority (i.e., greater than 50%) of the overall lengthL_(O). In some embodiments, the inner diameter ID may be constant alongonly a minority (i.e., less than 50%) of the overall length L_(O). Insome embodiments, the inner diameter ID may be constant along anentirety of the overall length L_(O). According to various embodiments,the inner diameter ID may be constant along a continuous portion of theshaft 110 having a length that is greater than 5%, greater than 10%,greater than 20%, greater than 30%, greater than 40%, greater than 50%,greater than 60%, greater than 70%, greater than 80%, or greater than90% of the overall length L_(O).

The inner diameter ID may continuously decrease along one or moreportions of the shaft 110 in a direction from the first end 112 towardthe second end 114 and/or the inner diameter ID may continuouslyincrease along one or more portions of the shaft 110 in the directionfrom the first end 112 toward the second end 114. In some embodiments,the inner diameter ID may continuously increase or continuously decreasein a linear manner along one or more portions of the shaft 110. In someembodiments, the inner diameter ID may continuously increase orcontinuously decrease in a non-linear manner along one or more portionsof the shaft 110. In this manner, the inner diameter ID may continuouslydecrease or continuously increase at a varying rate. Variouscombinations of one or more shaft portions having acontinuously-decreasing inner diameter ID, one or more shaft portionshaving a continuously-increasing inner diameter ID, and one or moreshaft portions having a constant inner diameter ID may be used toprovide a desired stiffness profile of the shaft 110.

The wall thickness T_(W) of the shaft 110 may continuously vary alongone or more portions of the overall length L_(O). According to variousembodiments, the wall thickness T_(W) may continuously vary along atleast 5%, at least 10%, at least 20%, at least 30%, at least 40%, atleast 50%, at least 60%, at least 70%, at least 80%, or at least 90% ofthe overall length L_(O). In some embodiments, the wall thickness T_(W)may continuously vary along at least a majority (i.e., greater than 50%)of the overall length L_(O). In some embodiments, the wall thicknessT_(W) may continuously vary along only a minority (i.e., less than 50%)of the overall length L_(O). In some embodiments, the wall thicknessT_(W) may continuously vary along an entirety of the overall lengthL_(O). According to various embodiments, the wall thickness T_(W) maycontinuously vary along a continuous portion of the shaft 110 having alength that is greater than 5%, greater than 10%, greater than 20%,greater than 30%, greater than 40%, greater than 50%, greater than 60%,greater than 70%, greater than 80%, or greater than 90% of the overalllength L_(O). In some embodiments, the wall thickness T_(W) may beconstant along one or more portions of the overall length L_(O).According to various embodiments, the wall thickness T_(W) may beconstant along at least 5%, at least 10%, at least 20%, at least 30%, atleast 40%, at least 50%, at least 60%, at least 70%, at least 80%, or atleast 90% of the overall length L_(O). In some embodiments, the wallthickness T_(W) may be constant along at least a majority (i.e., greaterthan 50%) of the overall length L_(O). In some embodiments, the wallthickness T_(W) may be constant along only a minority (i.e., less than50%) of the overall length L_(O). According to various embodiments, thewall thickness T_(W) may be constant along a continuous portion of theshaft 110 having a length that is greater than 5%, greater than 10%,greater than 20%, greater than 30%, greater than 40%, greater than 50%,greater than 60%, greater than 70%, greater than 80%, or greater than90% of the overall length L_(O).

The wall thickness T_(W) may continuously decrease along one or moreportions of the shaft 110 in a direction from the first end 112 towardthe second end 114 and/or the wall thickness T_(W) may continuouslyincrease along one or more portions of the shaft 110 in the directionfrom the first end 112 toward the second end 114. In some embodiments,the wall thickness T_(W) may continuously increase or continuouslydecrease in a linear manner along one or more portions of the shaft 110.In some embodiments, the wall thickness T_(W) may continuously increaseor continuously decrease in a non-linear manner along one or moreportions of the shaft 110. In this manner, the wall thickness T_(W) maycontinuously decrease or continuously increase at a varying rate. Invarious embodiments, the wall thickness T_(W) may be continuously variedover a particular portion of the shaft 110 by continuously varying theouter diameter OD, the inner diameter ID, or both the outer diameter ODand the inner diameter ID along the shaft portion. Various combinationsof one or more shaft portions having a continuously-decreasing wallthickness T_(W), one or more shaft portions having acontinuously-increasing wall thickness T_(W), and one or more shaftportions having a constant wall thickness T_(W) may be used to provide adesired stiffness profile of the shaft 110.

As shown in FIG. 1B, the golf shaft 110 may include a first shaftportion 141 along which the wall thickness T_(W) continuously varies,and a second shaft portion 142 along which the wall thickness T_(W)continuously varies in a manner different from the first shaft portion141. According to various embodiments, the shaft 110 may include anynumber of different shaft portions along which the wall thickness T_(W)continuously varies in different manners. As shown, the wall thicknessT_(W) may continuously decrease along the first shaft portion 141 in thedirection from the first end 112 toward the second end 114, and the wallthickness T_(W) may continuously increase along the second shaft portion142 in the direction from the first end 112 toward the second end 114.In some embodiments, as shown, the outer diameter OD may continuouslydecrease along each of the first shaft portion 141 and the second shaftportion 142. In some embodiments, as shown, the outer diameter OD maycontinuously decrease in a linear manner along each of the first shaftportion 141 and the second shaft portion 142. In some embodiments, asshown, the outer diameter OD may continuously decrease in a linearmanner along the entire intermediate section 126. In some embodiments,as shown, the outer diameter OD may continuously decrease in a linearmanner from the first end 112 to the second end 114. In someembodiments, as shown, the inner diameter ID may continuously increasealong the first shaft portion 141 and may continuously decrease alongthe second shaft portion 142. In some embodiments, as shown, the innerdiameter ID may continuously increase in a linear manner along the firstshaft portion 141 and may continuously decrease a non-linear manneralong the second shaft portion 142. It will be appreciated that variousconfigurations of different portions of the shaft 110 having acontinuously-varying wall thickness T_(W) may be achieved by varying oneor both of the outer diameter OD and the inner diameter ID along therespective portions of the shaft 110, as discussed above. Further, asdiscussed above, one or more other portions of the shaft 110 may beprovided with a constant wall thickness T_(W), which may be achieved byhaving the outer diameter OD and the inner diameter ID constant alongthe respective portions of the shaft 110 or by varying the outerdiameter OD and the inner diameter ID in the same manner along therespective portions of the shaft 110.

FIGS. 2A and 2B depict another example golf shaft 210 as may be used asa part of the golf club 100 of FIG. 1A instead of the shaft 110. Certainsimilarities and differences between the shaft 210 and the shaft 110described above will be appreciated from the drawings and the followingdescription. Corresponding reference numbers are used for correspondingfeatures, which generally may be configured in a manner similar to thefeatures described above unless indicated otherwise.

As shown, the golf shaft 210 may be formed as an elongated structurehaving a longitudinal axis A_(L). The shaft 210 may have a first end 212and a second end 214 disposed opposite one another along thelongitudinal axis A_(L) of the shaft 210. As shown, the shaft 210 mayhave an overall length L_(O) from the first end 212 to the second end214. The shaft 210 may include a first end section 222, a second endsection 224, and an intermediate section 226 extending from the firstend section 222 to the second end section 224. The first end section 222may be configured to receive the grip 150 thereon, and the second endsection 224 may be configured to receive the clubhead 160 thereon. Inthis manner, upon assembly of the golf club 100, the grip 150 may coverand be coupled to the first end section 222, and the clubhead 160 maycover and be coupled to the second end section 224, while theintermediate section 226 may remain exposed and not be covered by thegrip 150 or the clubhead 160.

The golf shaft 210 may define an internal cavity 230 extending along thelongitudinal axis A_(L) of the shaft 210. In this manner, the shaft 210may have a tubular shape along at least a portion of the shaft 210. Asshown, the cavity 230 may extend from the first end 212 toward thesecond end 214 and be spaced apart from the second end 214. In otherwords, the cavity 230 may begin at the first end 212 and terminate at alocation spaced apart from the second end 214. In this manner, thecavity 230 may extend along only a portion of the overall length L_(O)of the shaft 210, with the first end 212 being open and the second end214 being closed. As shown, a portion of the shaft 210 disposed betweenthe cavity 230 and the second end 214 may have a solid cross section(taken perpendicular to the longitudinal axis A_(L) of the shaft 210).As discussed above, various configurations of one or more internalcavities may be used in different embodiments.

The golf shaft 210 may have an outer surface 232 and an inner surface234. As shown in FIG. 2B, the inner surface 234 may define the cavity230. In some embodiments, as shown, each of the outer surface 232 andthe inner surface 234 may have a circular cross-sectional shape (takenperpendicular to the longitudinal axis A_(L) of the shaft 210). In thismanner, the shaft 210 may have an outer diameter OD, an inner diameterID, and a wall thickness T_(W), as shown in FIG. 2B. The wall thicknessT_(W) of the shaft 210 may continuously vary along one or more portionsof the overall length L_(O). In some embodiments, as shown, the wallthickness T_(W) may continuously vary along at least a majority of theoverall length L_(O). According to various embodiments, the wallthickness T_(W) may continuously vary along at least 5%, at least 10%,at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, atleast 70%, at least 80%, or at least 90% of the overall length L_(O). Insome embodiments, the wall thickness T_(W) may continuously vary alongan entirety of the overall length L_(O). According to variousembodiments, the wall thickness T_(W) may continuously vary along acontinuous portion of the shaft 210 having a length that is greater than5%, greater than 10%, greater than 20%, greater than 30%, greater than40%, greater than 50%, greater than 60%, greater than 70%, greater than80%, or greater than 90% of the overall length L_(O). In someembodiments, the wall thickness T_(W) may be constant along a minorityof the overall length L_(O).

The wall thickness T_(W) may continuously decrease along one or moreportions of the shaft 210 in a direction from the first end 212 towardthe second end 214 and/or the wall thickness T_(W) may continuouslyincrease along one or more portions of the shaft 210 in the directionfrom the first end 212 toward the second end 214. In some embodiments,the wall thickness T_(W) may continuously increase or continuouslydecrease in a linear manner along one or more portions of the shaft 210.In some embodiments, the wall thickness T_(W) may continuously increaseor continuously decrease in a non-linear manner along one or moreportions of the shaft 210. In this manner, the wall thickness T_(W) maycontinuously decrease or continuously increase at a varying rate. Invarious embodiments, the wall thickness T_(W) may be continuously variedover a particular portion of the shaft 210 by continuously varying theouter diameter OD, the inner diameter ID, or both the outer diameter ODand the inner diameter ID along the shaft portion. Various combinationsof one or more shaft portions having a continuously-decreasing wallthickness T_(W), one or more shaft portions having acontinuously-increasing wall thickness T_(W), and one or more shaftportions having a constant wall thickness T_(W) may be used to provide adesired stiffness profile of the shaft 210.

As shown in FIG. 2B, the golf shaft 210 may include a first shaftportion 241 along which the wall thickness T_(W) continuously varies, asecond shaft portion 242 along which the wall thickness T_(W)continuously varies in a manner different from the first shaft portion241, a third shaft portion 243 along which the wall thickness T_(W)continuously varies in a manner different from each of the first shaftportion 241 and the second shaft portion 242, and a fourth shaft portion244 along which the wall thickness T_(W) continuously varies in a mannerdifferent from each of the first shaft portion 241, the second shaftportion 242, and the third shaft portion 243. As shown, the shaft 210also may include a fifth shaft portion 245 that is disposed between thefourth shaft portion 244 and the second end 214 and is solid because thecavity 230 does not extend along the fifth shaft portion 245. Accordingto various embodiments, the shaft 210 may include any number ofdifferent shaft portions along which the wall thickness T_(W)continuously varies in different manners. As shown, the wall thicknessT_(W) may continuously decrease along the first shaft portion 241 in thedirection from the first end 212 toward the second end 214, the wallthickness T_(W) may continuously increase along the second shaft portion242 in the direction from the first end 212 toward the second end 214,the wall thickness T_(W) may continuously decrease along the third shaftportion 243 in the direction from the first end 212 toward the secondend 214, and the wall thickness T_(W) may continuously increase alongthe fourth shaft portion 243 in the direction from the first end 212toward the second end 214. In some embodiments, as shown, the outerdiameter OD may continuously decrease along each of the first shaftportion 241, the second shaft portion 242, the third shaft portion 243,and the fourth shaft portion 244. In some embodiments, as shown, theouter diameter OD may continuously decrease in a linear manner alongeach of the first shaft portion 241, the second shaft portion 242, thethird shaft portion 243, and the fourth shaft portion 244. In someembodiments, as shown, the outer diameter OD may continuously decreasein a linear manner along the entire intermediate section 226. In someembodiments, as shown, the outer diameter OD may continuously decreasein a linear manner from the first end 212 to the second end 214. In someembodiments, as shown, the inner diameter ID may be constant along thefirst shaft portion 241, may continuously decrease along the secondshaft portion 242, may continuously increase along the third shaftportion 243, and may continuously decrease along the fourth shaftportion 244. In some embodiments, as shown, the inner diameter ID maycontinuously decrease in a linear manner along the second shaft portion242, may continuously increase a linear manner along the third shaftportion 243, and may continuously decrease in a linear manner along thefourth shaft portion 244. It will be appreciated that variousconfigurations of different portions of the shaft 210 having acontinuously-varying wall thickness T_(W) may be achieved by varying oneor both of the outer diameter OD and the inner diameter ID along therespective portions of the shaft 210, as discussed above.

FIGS. 3A and 3B depict another example golf shaft 310 as may be used asa part of the golf club 100 of FIG. 1A instead of the shaft 110. Certainsimilarities and differences between the shaft 310 and the shafts 110,210 described above will be appreciated from the drawings and thefollowing description. Corresponding reference numbers are used forcorresponding features, which generally may be configured in a mannersimilar to the features described above unless indicated otherwise.

As shown, the golf shaft 310 may be formed as an elongated structurehaving a longitudinal axis A_(L). The shaft 310 may have a first end 312and a second end 314 disposed opposite one another along thelongitudinal axis A_(L) of the shaft 310. As shown, the shaft 310 mayhave an overall length L_(O) from the first end 312 to the second end314. The shaft 310 may include a first end section 322, a second endsection 324, and an intermediate section 326 extending from the firstend section 322 to the second end section 324. The first end section 322may be configured to receive the grip 150 thereon, and the second endsection 324 may be configured to receive the clubhead 160 thereon. Inthis manner, upon assembly of the golf club 100, the grip 150 may coverand be coupled to the first end section 322, and the clubhead 160 maycover and be coupled to the second end section 324, while theintermediate section 326 may remain exposed and not be covered by thegrip 150 or the clubhead 160.

The golf shaft 210 may define a plurality of internal cavities 330extending along the longitudinal axis A_(L) of the shaft 310. In thismanner, the shaft 310 may have a tubular shape along at least a portionof the shaft 310. As shown, the shaft 310 may define a first cavity 330a and a second cavity 330 b that are not in communication with oneanother. The first cavity 330 a may extend from the first end 312 towardthe second end 314 and be spaced apart from the second end 314, and thesecond cavity 330 b may extend from the second end 314 toward the firstend 312 and be spaced apart from the first end 312. In other words, thefirst cavity 330 a may begin at the first end 312 and terminate at alocation spaced apart from the second end 314, and the second cavity 330b may begin at the second end 314 and terminate at a location spacedapart from the first end 312. In this manner, each of the cavities 330a, 330 b may extend along only a portion of the overall length L_(O) ofthe shaft 310, with each of the first end 312 and the second end 314being open. As shown, a portion of the shaft 310 disposed between thecavities 330 a, 330 b may have a solid cross section (takenperpendicular to the longitudinal axis A_(L) of the shaft 310). Asdiscussed above, various configurations of one or more internal cavitiesmay be used in different embodiments.

The golf shaft 310 may have an outer surface 332 and a plurality ofinner surfaces 334. As shown in FIG. 3B, a first inner surface 334 a maydefine the first cavity 330 a, and a second inner surface 334 b maydefine the second cavity 330 a. In some embodiments, as shown, each ofthe outer surface 332, the first inner surface 334 a, and the secondinner surface 334 b may have a circular cross-sectional shape (takenperpendicular to the longitudinal axis A_(L) of the shaft 310). In thismanner, the shaft 310 may have an outer diameter OD, an inner diameterID, and a wall thickness T_(W), as shown in FIG. 3B. The wall thicknessT_(W) of the shaft 310 may continuously vary along one or more portionsof the overall length L_(O). In some embodiments, as shown, the wallthickness T_(W) may continuously vary along at least a majority of theoverall length L_(O). According to various embodiments, the wallthickness T_(W) may continuously vary along at least 5%, at least 10%,at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, atleast 70%, at least 80%, or at least 90% of the overall length L_(O). Insome embodiments, as shown, the wall thickness T_(W) may continuouslyvary along an entirety of the overall length L_(O). According to variousembodiments, the wall thickness T_(W) may continuously vary along acontinuous portion of the shaft 310 having a length that is greater than5%, greater than 10%, greater than 20%, greater than 30%, greater than40%, greater than 50%, greater than 60%, greater than 70%, greater than80%, or greater than 90% of the overall length L_(O). In someembodiments, the wall thickness T_(W) may be constant along a minorityof the overall length L_(O).

The wall thickness T_(W) may continuously decrease along one or moreportions of the shaft 310 in a direction from the first end 312 towardthe second end 314 and/or the wall thickness T_(W) may continuouslyincrease along one or more portions of the shaft 310 in the directionfrom the first end 312 toward the second end 314. In some embodiments,the wall thickness T_(W) may continuously increase or continuouslydecrease in a linear manner along one or more portions of the shaft 310.In some embodiments, the wall thickness T_(W) may continuously increaseor continuously decrease in a non-linear manner along one or moreportions of the shaft 310. In this manner, the wall thickness T_(W) maycontinuously decrease or continuously increase at a varying rate. Invarious embodiments, the wall thickness T_(W) may be continuously variedover a particular portion of the shaft 310 by continuously varying theouter diameter OD, the inner diameter ID, or both the outer diameter ODand the inner diameter ID along the shaft portion. Various combinationsof one or more shaft portions having a continuously-decreasing wallthickness T_(W), one or more shaft portions having acontinuously-increasing wall thickness T_(W), and one or more shaftportions having a constant wall thickness T_(W) may be used to provide adesired stiffness profile of the shaft 310.

As shown in FIG. 3B, the golf shaft 310 may include a first shaftportion 341 along which the wall thickness T_(W) continuously varies, asecond shaft portion 342 along which the wall thickness T_(W)continuously varies in a manner different from the first shaft portion341, a third shaft portion 343 along which the wall thickness T_(W)continuously varies in a manner different from each of the first shaftportion 341 and the second shaft portion 342, and a fourth shaft portion344 along which the wall thickness T_(W) continuously varies in a mannerdifferent from each of the first shaft portion 341, the second shaftportion 342, and the third shaft portion 343. According to variousembodiments, the shaft 310 may include any number of different shaftportions along which the wall thickness T_(W) continuously varies indifferent manners. As shown, the wall thickness T_(W) may continuouslyincrease along the first shaft portion 341 in the direction from thefirst end 312 toward the second end 314, the wall thickness T_(W) maycontinuously decrease along the second shaft portion 342 in thedirection from the first end 312 toward the second end 314, the wallthickness T_(W) may continuously increase along the third shaft portion343 in the direction from the first end 312 toward the second end 314,and the wall thickness T_(W) may continuously decrease along the fourthshaft portion 343 in the direction from the first end 312 toward thesecond end 314. In some embodiments, as shown, the outer diameter OD maycontinuously decrease along each of the first shaft portion 341, thesecond shaft portion 342, the third shaft portion 343, and the fourthshaft portion 344. In some embodiments, as shown, the outer diameter ODmay continuously decrease in a linear manner along each of the firstshaft portion 341, the second shaft portion 342, the third shaft portion343, and the fourth shaft portion 344. In some embodiments, as shown,the outer diameter OD may continuously decrease in a linear manner alongthe entire intermediate section 326. In some embodiments, as shown, theouter diameter OD may continuously decrease in a linear manner from thefirst end 312 to the second end 314. In some embodiments, as shown, theinner diameter ID may continuously decrease along the first shaftportion 341, may continuously increase along the second shaft portion342, may continuously decrease along the third shaft portion 343, andmay continuously increase along the fourth shaft portion 344. In someembodiments, as shown, the inner diameter ID may continuously decreasein a non-linear manner along the first shaft portion 341, maycontinuously increase in a non-linear manner along the second shaftportion 342, may continuously decrease a non-linear manner along thethird shaft portion 343, and may continuously increase in a non-linearmanner along the fourth shaft portion 344. It will be appreciated thatvarious configurations of different portions of the shaft 310 having acontinuously-varying wall thickness T_(W) may be achieved by varying oneor both of the outer diameter OD and the inner diameter ID along therespective portions of the shaft 310, as discussed above.

FIGS. 4A-4G depict another example golf shaft 410 as may be used as apart of the golf club 100 of FIG. 1A instead of the shaft 110. Certainsimilarities and differences between the shaft 410 and the shafts 110,210, 310 described above will be appreciated from the drawings and thefollowing description. Corresponding reference numbers are used forcorresponding features, which generally may be configured in a mannersimilar to the features described above unless indicated otherwise.

As shown, the golf shaft 410 may be formed as an elongated structurehaving a longitudinal axis A_(L). The shaft 410 may have a first end 412and a second end 414 disposed opposite one another along thelongitudinal axis A_(L) of the shaft 410. As shown, the shaft 410 mayhave an overall length L_(O) from the first end 412 to the second end414. The shaft 410 may include a first end section 422, a second endsection 424, and an intermediate section 426 extending from the firstend section 422 to the second end section 424. The first end section 422may be configured to receive the grip 150 thereon, and the second endsection 424 may be configured to receive the clubhead 160 thereon. Inthis manner, upon assembly of the golf club 100, the grip 150 may coverand be coupled to the first end section 422, and the clubhead 160 maycover and be coupled to the second end section 424, while theintermediate section 426 may remain exposed and not be covered by thegrip 150 or the clubhead 160.

The golf shaft 410 may define an internal cavity 430 extending along thelongitudinal axis A_(L) of the shaft 410. In this manner, the shaft 410may have a tubular shape along at least a portion of the shaft 410. Asshown, the cavity 430 may extend from the first end 412 toward thesecond end 414 and be spaced apart from the second end 414. In otherwords, the cavity 430 may begin at the first end 412 and terminate at alocation spaced apart from the second end 414. In this manner, thecavity 430 may extend along only a portion of the overall length L_(O)of the shaft 410, with the first end 412 being open and the second end414 being closed. As shown, a portion of the shaft 410 disposed betweenthe cavity 430 and the second end 414 may have a solid cross section(taken perpendicular to the longitudinal axis A_(L) of the shaft 410).As discussed above, various configurations of one or more internalcavities may be used in different embodiments.

The golf shaft 410 may have an outer surface 432 and an inner surface434. As shown in FIGS. 4B-4G, the inner surface 434 may define thecavity 430. In some embodiments, as shown, each of the outer surface 432and the inner surface 434 may have a circular cross-sectional shape(taken perpendicular to the longitudinal axis A_(L) of the shaft 410).In this manner, the shaft 410 may have an outer diameter OD, an innerdiameter ID, and a wall thickness T_(W), as shown in FIGS. 4C-4G. Thewall thickness T_(W) of the shaft 410 may continuously vary along one ormore portions of the overall length L_(O). In some embodiments, asshown, the wall thickness T_(W) may continuously vary along at least amajority of the overall length L_(O). According to various embodiments,the wall thickness T_(W) may continuously vary along at least 5%, atleast 10%, at least 20%, at least 30%, at least 40%, at least 50%, atleast 60%, at least 70%, at least 80%, or at least 90% of the overalllength L_(O). In some embodiments, the wall thickness T_(W) maycontinuously vary along an entirety of the overall length L_(O).According to various embodiments, the wall thickness T_(W) maycontinuously vary along a continuous portion of the shaft 410 having alength that is greater than 5%, greater than 10%, greater than 20%,greater than 30%, greater than 40%, greater than 50%, greater than 60%,greater than 70%, greater than 80%, or greater than 90% of the overalllength L_(O). In some embodiments, as shown, the wall thickness T_(W)may be constant along a minority of the overall length L_(O).

The wall thickness T_(W) may continuously decrease along one or moreportions of the shaft 410 in a direction from the first end 412 towardthe second end 414 and/or the wall thickness T_(W) may continuouslyincrease along one or more portions of the shaft 410 in the directionfrom the first end 412 toward the second end 414. In some embodiments,the wall thickness T_(W) may continuously increase or continuouslydecrease in a linear manner along one or more portions of the shaft 410.In some embodiments, the wall thickness T_(W) may continuously increaseor continuously decrease in a non-linear manner along one or moreportions of the shaft 410. In this manner, the wall thickness T_(W) maycontinuously decrease or continuously increase at a varying rate. Invarious embodiments, the wall thickness T_(W) may be continuously variedover a particular portion of the shaft 410 by continuously varying theouter diameter OD, the inner diameter ID, or both the outer diameter ODand the inner diameter ID along the shaft portion. Various combinationsof one or more shaft portions having a continuously-decreasing wallthickness T_(W), one or more shaft portions having acontinuously-increasing wall thickness T_(W), and one or more shaftportions having a constant wall thickness T_(W) may be used to provide adesired stiffness profile of the shaft 410.

As shown in FIGS. 4B-4G, the golf shaft 410 may include a first shaftportion 441 along which the wall thickness T_(W) continuously varies, asecond shaft portion 442 along which the wall thickness T_(W)continuously varies in a manner different from the first shaft portion441, a third shaft portion 443 along which the wall thickness T_(W) isconstant, a fourth shaft portion 444 along with the wall thickness T_(W)continuously varies in a manner different from each of the first shaftportion 441 and the second shaft portion 442, a fifth shaft portion 445along which the wall thickness T_(W) continuously varies in a mannerdifferent from each of the first shaft portion 441, the second shaftportion 442, and the fourth shaft portion 444, and a sixth shaft portion446 along which the wall thickness T_(W) continuously varies in a mannerdifferent from each of the first shaft portion 441, the second shaftportion 442, the fourth shaft portion 444, and the fifth shaft portion445. As shown, the shaft 410 also may include a seventh shaft portion447 that is disposed between the sixth shaft portion 446 and the secondend 414 and is solid because the cavity 430 does not extend along theseventh shaft portion 447. According to various embodiments, the shaft410 may include any number of different shaft portions along which thewall thickness T_(W) continuously varies in different manners. As shown,the wall thickness T_(W) may continuously decrease along the first shaftportion 441 in the direction from the first end 412 toward the secondend 414, the wall thickness T_(W) may continuously decrease along thesecond shaft portion 442 in the direction from the first end 412 towardthe second end 414, the wall thickness T_(W) may be constant along thethird shaft portion 443, the wall thickness T_(W) may continuouslyincrease along the fourth shaft portion 444 in the direction from thefirst end 412 toward the second end 414, the wall thickness T_(W) maycontinuously increase along the fifth shaft portion 445 in the directionfrom the first end 412 toward the second end 414, and the wall thicknessT_(W) may continuously increase along the sixth shaft portion 446 in thedirection from the first end 412 toward the second end 414. In someembodiments, as shown, the outer diameter OD may continuously decreasealong the first shaft portion 441, may continuously decrease along thesecond shaft portion 442, may be constant along the third shaft portion443, may continuously increase along the fourth shaft portion 444, maycontinuously decrease along the fifth shaft portion 445, maycontinuously decrease along the sixth shaft portion 446, and maycontinuously decrease along the seventh shaft portion 447. In someembodiments, as shown, the outer diameter OD may continuously decreasein a linear manner along the first shaft portion 441, may continuouslydecrease in a non-linear manner along the second shaft portion 442, maycontinuously increase in a non-linear manner along the fourth shaftportion 444, may continuously decrease in a non-linear manner along thefifth shaft portion 445, may continuously decrease in a linear manneralong the sixth shaft portion 446, and may continuously decrease in alinear manner along the seventh shaft portion 447. In some embodiments,as shown, the inner diameter ID may continuously increase along thefirst shaft portion 441, may continuously decrease along the secondshaft portion 442, may be constant along the third shaft portion 443,may continuously increase along the fourth shaft portion 444, maycontinuously decrease along the fifth shaft portion 445, and maycontinuously decrease along the sixth shaft portion 446. In someembodiments, as shown, the inner diameter ID may continuously increasein a linear manner along the first shaft portion 441, may continuouslydecrease in a non-linear manner along the second shaft portion 442, maycontinuously increase in a non-linear manner along the fourth shaftportion 444, may continuously decrease in a non-linear manner along thefifth shaft portion 445, and may continuously decrease in a linearmanner along the sixth shaft portion 446. It will be appreciated thatvarious configurations of different portions of the shaft 410 having acontinuously-varying wall thickness T_(W) may be achieved by varying oneor both of the outer diameter OD and the inner diameter ID along therespective portions of the shaft 410, as discussed above.

As discussed above, in certain embodiments, a golf shaft may include aninternal lattice structure disposed within a cavity of the shaft, theconfiguration and extent of which may be selected to vary the stiffnessprofile of the shaft. FIGS. 5A and 5B depict an example golf shaft 510that includes a shaft body and an internal lattice structure. In someembodiments, the golf shaft 510 may be used as a part of the golf club100 of FIG. 1A instead of the shaft 110. In various embodiments, any oneof the shafts 110, 210, 310, 410 described above may include an internallattice structure similar to that described with respect to shaft 510,implemented in a similar manner. In such embodiments, the structure ofthe shafts 110, 210, 310, 410 described above and depicted in thecorresponding figures may be considered to constitute the “shaft body”that in combination with the internal lattice structure may form theoverall shaft.

As shown, the golf shaft 510 may be formed as an elongated structurehaving a longitudinal axis A_(L). The shaft 510 may have a first end 512and a second end 514 disposed opposite one another along thelongitudinal axis A_(L) of the shaft 510. As shown, the shaft 510 mayhave an overall length L_(O) from the first end 512 to the second end514. The shaft 510 may include a first end section 522, a second endsection 524, and an intermediate section 526 extending from the firstend section 522 to the second end section 524. The first end section 522may be configured to receive the grip 150 thereon, and the second endsection 524 may be configured to receive the clubhead 160 thereon. Inthis manner, upon assembly of the golf club 100, the grip 150 may coverand be coupled to the first end section 522, and the clubhead 160 maycover and be coupled to the second end section 524, while theintermediate section 526 may remain exposed and not be covered by thegrip 150 or the clubhead 160.

As shown, the golf shaft 510 may include a shaft body 516 (which alsomay be referred to as simply a “body”) and an internal lattice structure518 (which also may be referred to as simply a “lattice structure”)integrally formed with the shaft body 516. The shaft body 516 may extendfrom the first end 512 to the second end 514. The shaft body 516 maydefine an internal cavity 530 extending along the longitudinal axisA_(L) of the shaft 510. In this manner, the shaft body 516 may have atubular shape along at least a portion of the shaft body 516. As shown,the cavity 530 may extend from the first end 512 to the second end 514.As discussed above, various configurations of one or more internalcavities may be used in different embodiments. As shown, the latticestructure 518 may be disposed within the cavity 530. The latticestructure 518 may extend along at least part of the length of the cavity530. In some embodiments, as shown, the lattice structure 518 may extendalong the entire length of the cavity 530. In some embodiments, asshown, the lattice structure 518 may extend from the first end 512 tothe second end 514. In some embodiments, as shown, the lattice structure518 may define a plurality of openings each having a polygonal shape,although other shapes of the openings may be used in other embodiments.Various configurations and arrangements of the lattice structure 518 maybe used to provide a desired stiffness profile of the shaft 510.

The shaft body 516 may have an outer surface 532 and an inner surface534. As shown in FIG. 5B, the inner surface 534 may define the cavity530. In some embodiments, as shown, each of the outer surface 532 andthe inner surface 534 may have a circular cross-sectional shape (takenperpendicular to the longitudinal axis A_(L) of the shaft 510). In thismanner, the shaft body 516 may have an outer diameter OD, an innerdiameter ID, and a wall thickness T_(W), as shown in FIG. 5B. The wallthickness T_(W) of the shaft body 516 may continuously vary along one ormore portions of the overall length L_(O). In some embodiments, asshown, the wall thickness T_(W) may continuously vary along at least amajority of the overall length L_(O). According to various embodiments,the wall thickness T_(W) may continuously vary along at least 5%, atleast 10%, at least 20%, at least 30%, at least 40%, at least 50%, atleast 60%, at least 70%, at least 80%, or at least 90% of the overalllength L_(O). In some embodiments, as shown, the wall thickness T_(W)may continuously vary along an entirety of the overall length L_(O).According to various embodiments, the wall thickness T_(W) maycontinuously vary along a continuous portion of the shaft body 516having a length that is greater than 5%, greater than 10%, greater than20%, greater than 30%, greater than 40%, greater than 50%, greater than60%, greater than 70%, greater than 80%, or greater than 90% of theoverall length L_(O). In some embodiments, the wall thickness T_(W) maybe constant along a minority of the overall length L_(O).

The wall thickness T_(W) may continuously decrease along one or moreportions of the shaft body 516 in a direction from the first end 512toward the second end 514 and/or the wall thickness T_(W) maycontinuously increase along one or more portions of the shaft body 516in the direction from the first end 512 toward the second end 514. Insome embodiments, the wall thickness T_(W) may continuously increase orcontinuously decrease in a linear manner along one or more portions ofthe shaft body 516. In some embodiments, the wall thickness T_(W) maycontinuously increase or continuously decrease in a non-linear manneralong one or more portions of the shaft body 516. In this manner, thewall thickness T_(W) may continuously decrease or continuously increaseat a varying rate. In various embodiments, the wall thickness T_(W) maybe continuously varied over a particular portion of the shaft body 516by continuously varying the outer diameter OD, the inner diameter ID, orboth the outer diameter OD and the inner diameter ID along the shaftportion. Various combinations of one or more shaft portions having acontinuously-decreasing wall thickness T_(W), one or more shaft portionshaving a continuously-increasing wall thickness T_(W), and one or moreshaft portions having a constant wall thickness T_(W) may be used toprovide a desired stiffness profile of the shaft 510.

As shown in FIG. 5B, the wall thickness T_(W) of the shaft body 516 maycontinuously vary along the entirety of the overall length L_(O).Specifically, the wall thickness T_(W) of the shaft body 516 maycontinuously decrease along the entirety of the overall length L_(O) inthe direction from the first end 512 toward the second end 514. In someembodiments, as shown, the outer diameter OD may continuously decreasefrom the first end 512 to the second end 514, and the inner diameter IDmay be constant from the first end 512 to the second end 514. In someembodiments, as shown, the outer diameter OD may continuously decreasein a linear manner from the first end 512 to the second end 514. It willbe appreciated that various configurations of different portions of theshaft body 516 having a continuously-varying wall thickness T_(W) may beachieved by varying one or both of the outer diameter OD and the innerdiameter ID along the respective portions of the shaft body 516, asdiscussed above.

As discussed above, in certain embodiments, a golf shaft may include anexternal geometric structure disposed along an outer surface of theshaft, the configuration and extent of which may be selected to providean aesthetic appeal and/or to increase performance characteristics ofthe shaft. FIGS. 6-10 depict example golf shafts 610, 710, 810, 910,1010 that each include a shaft body and an external geometric structure.In some embodiments, the golf shafts 610, 710, 810, 910, 1010 may beused as a part of the golf club 100 of FIG. 1A instead of the shaft 110.In various embodiments, any one of the shafts 110, 210, 310, 410described above may include an external geometric structure similar tothat described with respect to shafts 610, 710, 810, 910, 1010implemented in a similar manner. In such embodiments, the structure ofthe shafts 110, 210, 310, 410 described above and depicted in thecorresponding figures may be considered to constitute the “shaft body”that in combination with the external geometric structure may form theoverall shaft. In some embodiments, an external geometric structure mayitself constitute a golf shaft. In other words, such a golf shaft maynot include a shaft body as described herein but rather may be formedsolely by an external geometric structure as described herein. In thismanner, for such embodiments, the golf shaft may be devoid of anythin-walled cylindrical segments.

As shown in FIG. 6 , a golf shaft 610 may include a shaft body 616 andan external geometric structure 618 disposed along an outer surface ofthe shaft body 616. In some embodiments, the external geometricstructure 618 may have a pattern of geometric shapes, such as polygonalshapes. As shown, the external geometric structure 618 may have apattern of triangles. Patterns of other polygonal shapes ornon-polygonal shapes may be used in other embodiments. In someembodiments, as shown, the pattern of geometric shapes may be arepeating pattern. In other embodiments, the pattern of geometric shapesmay be a non-repeating pattern. Further, in other embodiments, theexternal geometric structure 618 may include various irregular ornon-geometric forms. As noted above, in some embodiments, the shaft body616 may be omitted, such that the external geometric structure 618itself constitutes the golf shaft 610, and the golf shaft 610 may bedevoid of any thin-walled cylindrical segments.

As shown in FIG. 7 , a golf shaft 710 may include a shaft body 716 andan external geometric structure 718 disposed along an outer surface ofthe shaft body 716. In some embodiments, the external geometricstructure 718 may have a pattern of geometric shapes, such as polygonalshapes. As shown, the external geometric structure 718 may have apattern of hexagons. In some embodiments, as shown, the pattern may forma honeycomb structure. Patterns of other polygonal shapes ornon-polygonal shapes may be used in other embodiments. In someembodiments, as shown, the pattern of geometric shapes may be arepeating pattern. In other embodiments, the pattern of geometric shapesmay be a non-repeating pattern. Further, in other embodiments, theexternal geometric structure 718 may include various irregular ornon-geometric forms. As noted above, in some embodiments, the shaft body716 may be omitted, such that the external geometric structure 718itself constitutes the golf shaft 710, and the golf shaft 710 may bedevoid of any thin-walled cylindrical segments.

As shown in FIG. 8 , a golf shaft 810 may include a shaft body 816 andan external geometric structure 818 disposed along an outer surface ofthe shaft body 816. In some embodiments, the external geometricstructure 818 may include one of more helixes centered on thelongitudinal axis A_(L) of the shaft 810. In some embodiments, as shown,the one of more helixes may be radially spaced apart from the shaft body816. As noted above, in some embodiments, the shaft body 816 may beomitted, such that the external geometric structure 818 itselfconstitutes the golf shaft 810, and the golf shaft 810 may be devoid ofany thin-walled cylindrical segments.

As shown in FIG. 9 , a golf shaft 910 may include a shaft body 916 andan external geometric structure 918 disposed along an outer surface ofthe shaft body 916. In some embodiments, the external geometricstructure 918 may have a pattern of geometric shapes, such as polygonalshapes. As shown, the external geometric structure 918 may have apattern of irregular hexagons, although regular hexagons may be used inother embodiments. Patterns of other polygonal shapes or non-polygonalshapes may be used in other embodiments. In some embodiments, as shown,the pattern of geometric shapes may be a repeating pattern. In otherembodiments, the pattern of geometric shapes may be a non-repeatingpattern. Further, in other embodiments, the external geometric structure918 may include various irregular or non-geometric forms. As notedabove, in some embodiments, the shaft body 916 may be omitted, such thatthe external geometric structure 918 itself constitutes the golf shaft910, and the golf shaft 910 may be devoid of any thin-walled cylindricalsegments.

As shown in FIG. 10 , a golf shaft 1010 may include a shaft body 1016and an external geometric structure 1018 disposed along an outer surfaceof the shaft body 1016. In some embodiments, the external geometricstructure 1018 may have a pattern of geometric shapes, such as polygonalshapes. As shown, the external geometric structure 1018 may have apattern of diamonds. Patterns of other polygonal shapes or non-polygonalshapes may be used in other embodiments. In some embodiments, as shown,the pattern of geometric shapes may be a repeating pattern. In otherembodiments, the pattern of geometric shapes may be a non-repeatingpattern. Further, in other embodiments, the external geometric structure1018 may include various irregular or non-geometric forms. As notedabove, in some embodiments, the shaft body 1016 may be omitted, suchthat the external geometric structure 1018 itself constitutes the golfshaft 1010, and the golf shaft 1010 may be devoid of any thin-walledcylindrical segments.

It will be appreciated that the configurations of the external geometricstructures 618, 718, 818, 918, 1018 shown in FIGS. 6-10 are merely a fewexamples of external geometric structures for a golf shaft, and thatvarious other configurations may be used in other embodiments.

Example Embodiments of Methods for Manufacturing Golf Shafts

The golf shafts 110, 210, 310, 410, 510, 610, 710, 810, 918, 1018described herein may be manufactured by various methods, including, insome instances, conventional shaft fabrication techniques, whenpossible. However, in view of complex geometries, such as shaft portionshaving a continuously-varying outer diameter, inner diameter, and/orwall thickness, internal lattice structures, and/or external geometricstructures according to different embodiments, the use of additivemanufacturing techniques may be particularly advantageous forfabricating the shafts 110, 210, 310, 410, 510, 610, 710, 810, 918,1018. Moreover, as discussed above, the use of additive manufacturingtechniques to fabricate the shafts 110, 210, 310, 410, 510, 610, 710,810, 918, 1018 advantageously may provide the ability to vary theshaft's wall thickness to provide an optimal stiffness profile for aparticular user or for a particular subset of users havingclosely-similar swing speeds, while avoiding the high tooling costsassociated with conventional shaft manufacturing methods. Furtherbenefits of using additive manufacturing over conventional techniqueswill be appreciated by one of ordinary skill in the art in view of theunique features and customizable nature of the shafts 110, 210, 310,410, 510, 610, 710, 810, 918, 1018.

An example method for manufacturing a golf shaft may include receiving aCAD model corresponding to the golf shaft, and forming, based at leastin part on the CAD model, the golf shaft using one or more additivemanufacturing techniques. The golf shaft may be any one of the shafts110, 210, 310, 410, 510, 610, 710, 810, 918, 1018 or variationsdescribed herein. In some embodiments, the golf shaft may be formed ofone or more metals or metal alloys using one or more metal additivemanufacturing techniques. In some embodiments, the one or more metals ormetal alloys may include at least one of: steel, a steel alloy,titanium, a titanium alloy, aluminum, or an aluminum alloy. In someembodiments, the golf shaft may be formed using one or more powder bedfusion techniques, such as direct metal laser sintering (DMLS),selective laser melting (SLM), or electron beam melting (EBM). In someembodiments, the golf shaft may be formed using one or more metal binderjetting techniques, such as 3D printing. In some embodiments, the golfshaft may be formed using one or more direct energy depositiontechniques, such as laser engineered net shaping (LENS), direct metaldeposition (DMD), or laser metal deposition (LIVID). In someembodiments, the golf shaft may be formed using metal materialextrusion. In some embodiments, the golf shaft may be formed using oneor more material jetting techniques, such as liquid metal additivemanufacturing. In some embodiments, the golf shaft may be formed usingjoule printing. In some embodiments, the golf shaft may be formed usingdigital light projection metal printing. In some embodiments, the golfshaft may be formed using cold spray metal printing. Still other typesof additive manufacturing techniques may be used in other embodiments.In some embodiments, the golf shaft may be formed as a single componentusing additive manufacturing techniques. In some embodiments, two ormore segments of the golf shaft may be separately formed using additivemanufacturing techniques and then fixedly coupled to one another, forexample, by welding. This approach may be used, for example, when theadditive manufacturing equipment being used is not able to accommodatefabrication of a single component having the desired overall length ofthe golf shaft. As discussed above, the golf shaft may be customized fora particular user based on one or more characteristics of the user'sswing pattern. Accordingly, in some embodiments, the method also mayinclude determining user data corresponding to a swing pattern of apredetermined user of the golf shaft, and generating the CAD model basedat least in part on the user data. In some embodiments, a stiffnessprofile of the golf shaft may be determined based at least in part onthe user data, and the CAD model may be generated based at least in parton the stiffness profile.

Although various types of additive manufacturing techniques may be usedto produce the golf shafts described herein, SLM or DMLS may beparticularly well suited for manufacturing the shafts. Exampleparameters for manufacturing the golf shafts via SLM or DMLS may includeone or more (in any combination), or all, of the following: a powderparticle size of greater than 1 nm and less than 1 mm; a continuous orpulsed laser with a wavelength of greater than 1 nm and less than 1 m; alaser power of greater than 0 W and less than 20,000 W; a layerthickness of greater than 0 mm and less than 2 mm; a scan speed ofgreater than 0 mm/s and less than 20,000 mm/s; a build plate temperatureof greater than 0° C. and less than 500° C.; use of a soft silicone,brush, or metal recoating blade; and use of an argon, nitrogen, or inertgas atmosphere.

Although specific embodiments of the disclosure have been described, oneof ordinary skill in the art will recognize that numerous othermodifications and alternative embodiments are within the scope of thedisclosure. For example, while various illustrative implementations andstructures have been described in accordance with embodiments of thedisclosure, one of ordinary skill in the art will appreciate thatnumerous other modifications to the illustrative implementations andstructures described herein are also within the scope of thisdisclosure.

Although embodiments have been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the disclosure is not necessarily limited to the specific featuresor acts described. Rather, the specific features and acts are disclosedas illustrative forms of implementing the embodiments. Conditionallanguage, such as, among others, “can,” “could,” “might,” or “may,”unless specifically stated otherwise, or otherwise understood within thecontext as used, is generally intended to convey that certainembodiments could include, while other embodiments do not include,certain features, elements, and/or steps. Thus, such conditionallanguage is not generally intended to imply that features, elements,and/or steps are in any way required for one or more embodiments.

What is claimed is:
 1. A golf shaft comprising: a first end; and asecond end disposed opposite the first end along a longitudinal axis ofthe golf shaft, wherein the golf shaft defines one or more internalcavities extending along the longitudinal axis, wherein the golf shafthas an overall length from the first end to the second end, an outerdiameter, an inner diameter, and a wall thickness, wherein the wallthickness varies along the overall length, and wherein a variation ofthe wall thickness between any two cross-sections of the golf shafttaken perpendicular to the longitudinal axis is equal to or greater than0.001 inches.
 2. The golf shaft of claim 1, wherein at least one of theinner diameter or the outer diameter varies in a non-linear manner alongat least a portion of the golf shaft.
 3. The golf shaft of claim 1,wherein at least one of the inner diameter or the outer diameter variesalong at least a portion of the golf shaft such that a taper rate of theat least one of the inner diameter or the outer diameter changes morethan once along the at least a portion of the golf shaft.
 4. The golfshaft of claim 1, wherein the golf shaft comprises one or more metals ormetal alloys.
 5. The golf shaft of claim 1, wherein the golf shaftcomprises a single component.
 6. The golf shaft of claim 1, furthercomprising an internal lattice structure disposed within at least one ofthe one or more internal cavities.
 7. The golf shaft of claim 1, furthercomprising an external geometric structure disposed along an outersurface of the golf shaft, and wherein the external geometric structurehas a pattern of geometric shapes.
 8. The golf shaft of claim 7, whereinthe pattern of geometric shapes is a repeating pattern.
 9. A method formanufacturing a golf shaft, the method comprising: receiving a CAD modelcorresponding to the golf shaft; and forming, based at least in part onthe CAD model, the golf shaft using one or more additive manufacturingtechniques, the golf shaft comprising: a first end and a second enddisposed opposite one another along a longitudinal axis of the golfshaft, wherein the golf shaft defines one or more internal cavitiesextending along the longitudinal axis, wherein the golf shaft has anoverall length from the first end to the second end, an outer diameter,an inner diameter, and a wall thickness, wherein the wall thicknessvaries along the overall length, and wherein a variation of the wallthickness between any two cross-sections of the golf shaft takenperpendicular to the longitudinal axis is equal to or greater than 0.001inches.
 10. The method of claim 9, wherein at least one of the innerdiameter or the outer diameter varies in a non-linear manner along atleast a portion of the golf shaft.
 11. The method of claim 9, wherein atleast one of the inner diameter or the outer diameter varies along atleast a portion of the golf shaft such that a taper rate of the at leastone of the inner diameter or the outer diameter changes more than oncealong the at least a portion of the golf shaft.
 12. The method of claim9, wherein forming the golf shaft using one or more additivemanufacturing techniques comprises forming the golf shaft of one or moremetals or metal alloys using one or more metal additive manufacturingtechniques.
 13. The method of claim 9, wherein forming the golf shaftusing one or more additive manufacturing techniques comprises formingthe golf shaft as a single component using the one or more additivemanufacturing techniques.
 14. The method of claim 9, further comprising:determining user data corresponding to a swing pattern of apredetermined user of the golf shaft; generating the CAD model based atleast in part on the user data.
 15. The method of claim 14, furthercomprising determining a stiffness profile of the golf shaft based atleast in part on the user data, wherein generating the CAD model basedat least in part on the user data comprises generating the CAD modelbased at least in part on the stiffness profile.
 16. The method of claim9, wherein the golf shaft further comprises an internal latticestructure disposed within at least one of the one or more internalcavities.
 17. The method of claim 9, wherein the golf shaft furthercomprises an external geometric structure disposed along an outersurface of the golf shaft, and wherein the external geometric structurehas a pattern of geometric shapes.
 18. A method for manufacturing a golfshaft, the method comprising: receiving a CAD model corresponding to thegolf shaft; and forming, based at least in part on the CAD model, thegolf shaft using one or more additive manufacturing techniques, the golfshaft comprising: a first end; a second end disposed opposite the firstend along a longitudinal axis of the golf shaft, wherein the golf shafthas an overall length from the first end to the second end; a shaft bodyextending from the first end to the second end and having an outersurface, wherein the shaft body defines an internal cavity extendingalong the longitudinal axis; and an external geometric structuredisposed along the outer surface, wherein the external geometricstructure has a pattern of geometric shapes.
 19. The method of claim 18,wherein the pattern of geometric shapes is a repeating pattern.
 20. Themethod of claim 18, wherein the pattern of geometric shapes is anon-repeating pattern.